The Master also covered this in 1986: Do the menstrual cycles of women living together tend to synchronize? - The Straight Dope
…and then in 2002: Does menstrual synchrony really exist? - The Straight Dope
Short story: pretty dubious.
Apparent clustering of menstrual onsets doesn’t necessarily mean anything. Assuming an average cycle of 28 days, the maximum time between two women’s onsets is 14 days. Since the minimum is zero, the average difference — what you’d expect purely by chance — is seven days, and half the time would be less…
Shagnasty:
I didn’t take the idea presented in the OP the same way that many of you are. Some of you are assuming that the girlfriend meant that just being around another pregnant woman could make her pregnant. I don’t think that is what she meant. The idea, whether it is just an old wive’s tale or not, is that being around a pregnant woman can make you more likely to get pregnant yourself if you have sex shortly after being around them.
From the OP:
I would say with a gf saying that, the OP has a situation on his hands.
Leo_Bloom:
Yes, and her squeeing in excitement, whatever that is, sounds kinky. Unless you’re into that.*
*Since you’re new here–stick around!–being obnoxious about typos is often mandatory.
Um, yeah, just wander into any thread with cat pics and you’ll encounter massive squeeing.
Really_Not_All_That_Bright:
A condom fails when it leaks. The probability of a leak occurring does not increase with exposure to pregnant chicks- unless they are the sort who want to share the miracle of birth with their friends and poke at the OP’s wallet with needles.
The idea that being around pregnant women could increase the probability of conception assuming a leak does occur has some merit until you actually think about it: there are still only two eggs available for babby-forming.
Keeve:
I think most of the posters here - with the exception of bldysabba - are misunderstanding the OP.From this point, it is clear to me that there IS a man involved, and the claim is that contraceptives are irrelevant.
My understanding is that as a point of fact there are no contraceptives which work 100% of the time. All of them have a small failure rate, even when used properly. It sounds to me like the friends claim is not that pheromones will cause pregnancy even without sperm, but that the pheromones will cause the contraception to fail – or at least, increase the likelihood that the contraception will fail.
Given that all contraceptives will occasionally fail even when used correctly, how can one prove which factors caused it to fail? Or which factors did NOT cause it to fail?
When a condom leaks, it doesn’t inevitably cause pregnancy, it introduces a chance that pregnancy will ensue - a small leak will result in a smaller chance of pregnancy than a catastrophic leak - in exactly the same way that a low sperm count makes conception less likely.
I think the assertion being made by the OP’s GF (if it has any reasoned basis at all) is that the female will be somehow hyper-fertile in a way that will amplify even the tiniest risk of pregnancy into a certainty.
Of course, it doesn’t make much sense.
That should just wipe off.
And you didn’t even include a cat pic as an example ?
Here , I’ll do it for you…
Well, myself, I see two possibilities:
The OP’s girlfriend actually believes what she’s saying.
She’s just looking for an excuse not to have sex with him.
In the absence of any further context from the OP himself, I’d put my money on #2 .
Heh. Cute. He looks just like Nibbler from Futurama.