"cheating" at sex...paranoid

That is a terrible way to decide if a woman is pregnant. Many women spot and so appear to be having a period; other women have very irregular periods anyway and might have one or might not, so the appearance and especially the lack of one doesn’t mean anything.

I believe there are pregnancy tests now that are accurate within a couple of days after conception. Not sure. It doesn’t take weeks like it did in the olden days.

It is very foolish for someone who might be pregnant and does not want to be pregnant to simply wait for a period to show up. That might be fine though for someone who does, in fact, wish to be pregnant.

For an accurate way of knowing if she’s pregnant, a pregnancy test at her doctor’s would probably be the best bet.

Is it too late for the morning after pill at this point? (Not sure when “the other day” was.)

Look into getting the morning after pill right away. Here is a website with info about it: http://ec.princeton.edu/

You will also want to be checked for sexually transmitted diseases. Even if there are no symptoms it’s possible to have something without knowing it. Same goes for your girlfriend.

Not sure why you didn’t use a condom but they are pretty much a must unless you are with a partner you wish to have kids with. I have no idea of your age or location but I’m going to assume you are young enough that you can’t afford em and in a place where they are not freely distributed. You might be able to find a sexual health clinic which will provide free condoms - if not then you need to have sex without penetration or ejaculating near her vagina. There are plenty of things you can do that don’t involve pregnancy or disease risks.

Sex is a wonderful thing, and I understand being achingly horny and having a partner who is feeling the same way. Please use birth control from now on, and don’t fool yourself that you are not already having sex.

Edited to add that in my youth, the pill for the female was fine, but I came of age pre-HIV/AIDS, and let me amend birth control to condoms.

How long ago was “the other day”?

Get a morning after pill ffs!

Considering the current state of sex education in this country the OP could be considered over-educated.

IANA anything pertinent, but since everybody else seems to be tripping over each other trying to scold our poor OP instead of answering his question, here goes my best shot at it. It might not be spot on, but I hope it will spur someone more knowledgeable to answer.

Conception can occur anywhere up to 48 hours after you have sex. A blood pregnancy test (not the home urine type) will show a result about 2 or 3 days after conception. So you can trust a negative from a doctor’s test after 5 days from the time you had sex. Give or take.

Now I join the pile on. Yes, you were having sex. Yes, you need to start using protection. The doctor you will see for the pregnancy test can bury you under pamphlets for all your options. Read them.

It’s pretty hard to determine what the chances were of insemination occurring, as there are many factors involved. For the sake of discussion, let’s say it was a 10% chance. The problem is, if you’re in that unlucky 10%, she’s 100% pregnant.

I would say there’s no sense wallowing in worry (can’t undo the past, and the odds are in your favor), but it would make sense to give some thought to a course of action should there be a pregnancy.

This is what comes of “Abstinence Education”. No child left behind–or indeed, unconceived. Jesus H. Crunchberry, you’d think sex is akin to quantum mechanics, so many people have massive misconceptions about it.

Dude, ring up the local pharmacy or Planned Parenthood center and inquire what the requirements are to get Plan B, NorLevo, Levonelle, or whatever form of emergency post-hoc contraception is available. Second, get information one what is required to get your girlfriend on regular contraception AND buy yourself a package of condoms. After that, hie the down to the library or bookstore with the young lady in question and both of you need to spend a few hours perusing the material in the “sex education” section.

And Q.E.D., nice one.

Stranger

Dude,
Before you attack her, cover your wacker.
:smiley:

***This is the very first time you EVER ejaculated, and you did it inside and/or with the assistance of another living human being??? ***Are you saying that you never . . . I mean surely you must have . . . jeez, you missed out on all the years of . . . How old did you say you are?

The second bout of penetration after the first withdrawal and ejaculation seems to be the most unusual part of this event, and the most likely to increase the risk of pregnancy.

Eh?

I think everyone’s in agreement here that it’s pretty likely insemination occured. Conception on the other hand, is what we’re unsure of.

After an event has occurred, the odds of it happening are 100%.

Are you in college? If so, there’s almost certainly either a student group, or someone in your Health Services office, who can talk to you about how to practice safer sex. You’ve gotten superb advice in this thread - good Ford, I love Dopers - but it might be useful to talk to an actual live human being, as well. If nothing else, they could show you how to properly put on a condom. (They use a wooden model.)

Which event?

Insemination, yes pretty much 100%. Conception, we don’t know.

I’m trying to come up with a Schroedinger’s Pregnancy joke, but I’m stuck.

Yes, but the OP is not asking us to divine whether his girfriend is pregnant or not, he’s asking how big of a risk did he just take. We can talk about that, even though we don’t know the outcome of that risky action.

Probability is a measure of an epistemological state. The probability of X, where X is a sentence, is directly related to (roughly speaking) the certainty we have that X is true.

So it makes sense to ask “What is the probability that this occured?” This is the same as asking (roughly speaking) “How certain am I (or ought I to be) that this occured?”

-FrL-