Understanding how pregnancy works

[mmthomas12]

Hi all,

I recently posted regarding periods and unprotected sex. I realize that it's EXTREMELY unlikely that I got pregnant from my question a few days ago. I'm still confused about pregnancy and periods

-- For example: if I had unprotected sex on a Saturday and my period was due the next day, Sunday, I would still get my period, correct? I read that pregnancy takes some time to occur. So even if I got my period, I still have a chance to get pregnant and I would have to wait until my next period. Is that correct or am I misunderstanding?

[Heather]

So, here's the scoop: menstrual periods occur because of messages sent by the brain and hormones after ovulation, and up until the time a period begins. Most often, periods occur around two weeks after ovulation.

If and when people become pregnant, that process will first start with an activity that can create a pregnancy that occurred just before or right during ovulation. And when that happens, those messages the brain and hormones normally send to menstruate are overridden, basically. Thus, for most pregnant people, they first realized they were when they missed a period.

Not only is it very unlikely for anyone to be ovulating one day before a period, if they get a period the next day, they can be sure they weren't ovulating one day before, which means that even if they had had intercourse the day before, a pregnancy was not a real possibility.

Yes, pregnancy takes some time to occur, but the right conditions for it have to be there, and one of the biggest and most primary ones is an available ovum to fertilize. Another is the condition of the vagina being conducive to conception. Sperm cells can potentially stay viable within the vagina or fallopian tubes for 5-7 days, but very few people will have a period and ovulate, both, within a seven day window. That would be incredibly rare, not to mention that vaginal conditions around the time of and during menstruation aren't very hospitable to sperm cells or the process of conception.

That all make more sense now?

[Heather]

By the way, I really appreciate you asking for facts like this, and so plainly, in a new thread.

Even though they're based on a risk or a scare, separating them from that makes a big difference for us (and, I think, for any of you having scares, too).

[mmthomas12]

Yes, that makes a lot of sense. Lastly, does the same apply for withdrawal bleeds? I understand they are different and occur when there is withdrawal on the hormones of the pill.

Thanks! Yes, no problem. I'm trying to better educate myself so I don't freak out again (likely over nothing).

[Heather]

They're a little different, but not really, because withdrawal bleeds happen for similar reasons, it's just that some of the hormonal messages being sent to have flow (and not become pregnant) are being sent by the hormonal method. And just like for those not using those methods, if and when pregnancy occurs, people using hormonal methods will also almost always miss that "period."

[mmthomas12]

Cool, thanks! Makes sense.