So, you take your birth control pills every day like a good girl, and then one day you miss one. Doesn’t that trigger menstruation? (I mean, obviously it does.) So how do you get pregnant at that part in your artificially controlled cycle? Is there something I don’t understand about how the pill works? (Is it that people who get pregnant by missed pills are probably in the habit of missing them?)
Not a doctor or a medical professional, just somebody who’s read the info packets that came with her oral contraceptives…
IIRC, missing just **one **pill won’t make you fertile–it takes at least two or three. Oral contraceptives work by inhibiting your normal fertility, so by removing the extra hormones from your system, your body returns to its natural state.
Missing a pill does not trigger menstruation. Not sure why you think that, or why you thought it was so obvious that it would. Since it doesn’t. (At least, not immediately/right away/rightthisverysecond, which is how I read your post.)
The pillworks by suppressing ovulation AND changing the thickness of the cervical mucus AND probably something else I’ve forgotten.
Stop taking the pill, and those effects cease to be produced. The more pills you miss, the more your protection wears away.
It also depends on where in the cycle you are, I believe. If it’s the couple days before you would normally go off the pill for a week (or take the iron pills), it wouldn’t matter. But if you miss three days in the second week, you might have more problems…
It depends on several things - what type of pill you take (1, 2 or 3 phases), what the dosage of the pill is, what week you are in and how many you miss.
My pill packaging explains the procedure if you miss a pill, and whether a backup method is needed, depending on the exact circumstances. All this is explained in detail for each unique formulation in the packaging.
Usually (I don’t know the facts for every brand) missing one pill is not a problem. However, the chance of pregnancy while taking the pill correctly (never missing any) is not zero. Low, but not zero. So there is always the chance that you are the .002% freak. Some people are superfertile.
I forgot an important detail - a lot of people (like me, I was thinking about it when I took mine this morning which is why I asked) take them continuously. Missing a pill starts menstruation in that case within two days. In other words, you’re not ovulating when you miss one.
When you bleed from stopping the pill, it is a not a ‘period’ (by which I mean the normal shedding of the endometrium of the uterus because a fertilized egg from that month’s ovulation has failed to implant). It is ‘breakthrough bleeding’ from the withdrawal of the ovulation-suppressing hormones. When you are on hormonal BC, your body ‘thinks’ it is pregnant, even when you don’t take it for a week. It takes some time for the hormones to fully leave your body, and to start a proper cycle with normal ovulation - sometimes a long time, up to a year.
And yes, you *can *get pregnant from missing 1 pill (it would be a rare occurrence depending on several factors such as your natural hormone levels, when in month you missed the dose, and the type of BC you are using), or by taking antibiotics which can negate the pill’s affect on your body somewhat. You can ovulate when you miss a dose (not necessarily that day), and once an egg is released, pregnancy is possible whether or not you continue taking BC pills.
And then you have my friend, who took the pill accurately and correctly all through college, went off it after her wedding, thinking “oh we will try to have kids it will take a few months,” and got pregnant the same week.
When it comes to reproduction, YMMV. Really, really V.
How does your body “know” where you are, though? Like, if you stop taking your pill and start taking the sugar pills instead, you start bleeding but you can’t get pregnant in that week. But what about if you have unprotected sex after missing three days in the second week? Why is that different?
Also when you’re taking the sugar pills (for the week before you start a new pack), what if you didn’t take the pill after that? Like, you’re on the pill for three weeks, you stop taking it to take the sugar pills. While doing that you’re still having sex. But then you decide to stop taking the pill all together. Can you get pregnant?
If you’re taking active pills continuously, is your body just “on hold” in mock pregnancy? What stage of the cycle do you enter, probably, when you go off them, if you aren’t having a true menstrual period?
Yes.
If you have sperm inside you (which can live up to a week, rarely but it has happened), and an egg is released, you can get pregnant. If you are faffing about with your pills, an egg could theoretically be released at any time. If you are doing what you describe, you’re playing with fire. At the very least get your partner to pull out in a timely fashion!
Yes, your body is on hold, but it will resume ovulation as soon as it is able when the fake hormones are no longer at high enough levels to prevent ovulation, or if not ovulation the build-up of your endometrium (ovulation is not necessary to have a true period). This varies from woman to woman, but can happen very quickly, so beware.
As for what your body does when it resumes normal cycling… it totally depends on the individual, I think. Some have breakthrough bleeding after stopping the pill. Some don’t. Some ovulate right away, then have a true period (or don’t, because they got pregnant!!). I don’t think there’s any way to predict what will happen to you in these circumstances.
Effective (IN TIME) withdrawal was recently proven to be as effective as proper condom use. If you don’t want to use condoms, have the man pull out, even if you are on the pill. If you’re not having sperm deposited in you, your chances of pregnancy are nil (apart from the very rare cases where a ‘stray sperm’ somehow got up in there and led to pregnancy…).
Cite? And did they include every time the male mistimed the pull-out, or only the occasions where he did it perfectly? And what about the old addage about men being like basketball players?
ISTR that the risk of pregnancy associated with missing one or two pills in a row is because of that downward spike in hormone levels. Even if the pill keeps you at a “baseline” that is above normal and therefore in mock pregnancy, the dip below baseline can be enough to cause ovulation. Off the pill, that’s what happens normally - I think it’s the estrogen that dips, ovulation occurs, and then the hormone goes back up a little (though maybe not to what it was pre-ovulation).
I could be completely wrong about that, but it’s somehow the idea of it that I had formed in my head over the years! Can anyone confirm or deny this for me?
The primary contraceptive effect of the normal combo birth control pill (possibly the only one; recent research is a little unclear) is the suppression of ovulation. Miss a dose, you might ovulate. Ovulate, you might get pregnant. The bleeding you see when you miss doses (or someone on a ‘regular’ pill-taking schedule enters the placebo/no pills week) is not a normal period, though it might look one. It’s not triggered by the same hormone cycle, so there’s no “well, I’m having my period now, so I must have ovulated (except I didn’t) a couple of weeks ago”; if ovulation happens, it can happen at any time. This is one reason why women who get pregnant on the Pill have a lot of uncertainly regarding their due dates unless they get a dating ultrasound early on.
Incidentally, the whole “Use HBC to regulate your period” phrase is scientifically null for the same reason: when you’re on the pill, you do not have a “period” (that is, true menstruation) of any sort, even if you do periodically bleed.
What is “true menstruation”?
My experience has shown this to be true too.
I became pregnant twice in less than 6 months while being on the pill, and to the best of my knowledge and recollection, while taking it correctly. I don’t recall having missed any pills during the times I became pregnant. (Although I was on the “lo dose” pills at the time and suspect that maybe that had something to do with it because for years before that, I never had any other accidents while on regular strength pills.)
Since accident #2, we have strictly practiced withdrawal in addition to birth control pills (the full-strength kind), and in that time (2 years) I haven’t gotten pregnant again.
When you think about it, pulling out (on time of course) vastly reduces amount of sperm that will get into the vagina to close to zero. So that plus the pill seems to be a combo that highly increases your chances of successful pregnancy prevention.
My condolences.
So if its not a real period while on the pill, what is it exactly? What is the difference?
IANAD, just a contraceptive professional 
First some background info on how the pill works, in general, both to address some questions and just for purposes of completeness:
There are two basic kinds of birth control pills (BCPs), the combined oral contraceptive with both estrogen and progesterone, and the progesterone-only pill (“minipill” or “POP”). For the purposes of this discussion, assume we’re talking about the combined oral contraceptives. POPs are much more sensitive in terms of consistent use for contraceptive efficacy.
Birth control pills are mostly set up on a 28 day cycle. This mimics the body’s natural cycle, and is also handy, calendar-wise. For the sake of both convenience and efficacy, it’s recommended that you begin an initial cycle of pills with the first day of your next normal menstrual period, or at least within the first five days. For convenience, a “Sunday start” is often advised.
It takes seven days’ worth of continuous BCP use to effectively suppress ovulation, and for about 65% of women that first seven days is a pretty effective grace period of infertile days. If you line up the first week of your pills with the first infertile week of your cycle, you are considered protected immediately, though of course a backup method is always strongly recommended for a variety of reasons. You’re also more likely to have a smoother transition if you match the pill cycle up with your body’s normal cycle.
If you start your pills anywhere else during the cycle (say, two days before your body is due to ovulate), you cannot be assured of having sufficient hormone levels to suppress ovulation for that cycle, thus a backup method is strongly recommended for the first round. Mid-cycle spotting or “breakthrough bleeding” is more common when your pill cycle is initially misaligned with your normal menstrual cycle (only initially, not forever). No matter what day of the week or cycle you start, you take one pill a day, at the same time every day, either running left-to-right or clockwise in your pack. Do not skip a day, when you complete the placebo week of one pack start immediately on the next with no missed days in between.
If you start a pill pack (patch or NuvaRing) in conjunction with emergency contraception use, it doesn’t matter where you are at in your normal fertility cycle, just take the EC, start your new cycle of contraception, use a backup method for the next seven days. Expect some breakthrough bleeding, which is annoying but normal.
There are some variations on the hormone levels (mono- vs. tri-phasic, etc) but in general what you get is three weeks of “active” pills and one week of placebo pills.
Okay, so you started your pills on time the first time, you’ve taken them faithfully, and you come to the first of your placebo pills, generally differently-colored pills in the last row or 9-12 position in the pack. You are still considered protected in terms of contraception through this week of placebo pills because you have built up sufficient levels of hormone in your body to carry you through those seven days, but you *must * and I cannot emphasize that strongly enough, *must *start your next pack of pills on time. This is GQ and with my copy of Contraceptive Technology not immediately at hand, I’m not going to throw out an actual percentage, but the odds are drastic that being a day or two late with your pills will trigger a released egg. Missing the first pill in the pack (first patch in the cycle, first day of the NuvaRing) is the number one cause of “user error” pregnancies with combined methods.
So… if you can go seven days on placebos and be okay, why is it such a big deal if you miss one during the cycle? Well, it depends. If you are in week one of your pack and you miss a pill, you may not have built up sufficient levels of hormone to effectively suppress ovulation. Should you miss a pill during week one, and if you had unprotected sex, you should take Plan B, start a new pack of pills, and use condoms for the next seven days. A missed pill during week two? Not such a big deal–miss one, take both the next day and continue on as normal. Miss two active pills, take two today, two tomorrow, continue on with a seven-day backup method. Same story with week 3, if you are a Sunday starter just toss the old pack on Sunday and start your new one, even if you have another day or two of placebo pills left in the pack.
If you miss three or more pills at any point, take Plan B if needed, start a new pack from day one and continue on with a seven-day-backup-method.
What happens after ovulation.
It’s what’s called a “withdrawal bleed”. Remember that 28-day pill cycle I mentioned? The only reasons the packs are set up that way is pure convenience. The makers of the original pill figured that women wouldn’t want to take it if they didn’t feel “normal”, and a big part of “normal” for many women is bleeding with a certain regularity. Some feel like it’s the only way they can be sure they’re not pregnant, some just feel like it’s “wrong” not to bleed routinely. Basically, if you’re on a monophasic pill (where the pills are the same dose of hormones from day 1-21), it doesn’t matter whether your active cycle is three weeks, six weeks, ten weeks, or three months as far as contraception goes. Any value over 21 days of active pills will protect you for a seven-day placebo week. That’s what the whole “tri-cycling” thing is about, where you can skip the placebo pills and go straight into a new pack. You can more or less set yourself up on any schedule you like, assuming you have the right pill and your body lets you do so. Some pills are better for this than others, and some women’s bodies are more accommodating. The bleeding you experience only happens because you artificially trigger a drop in hormones, which causes a token bleed. It’s not “menstruation” though.
Suppressing the buildup of endometrial lining, thereby reducing the likelihood that an escaped fertilized egg finds a snuggly, comfy place to implant.
Primarily though, ovulatory suppression.