Testing after a withdrawal bleed

[honeybee12]

Dear Scarleteen,

As I understand it, if you take the pill perfectly you will not get pregnant, and you will not ovulate. In the off chance that breakthrough ovulation did occur would it occur mid-cycle? Or could it occur a few days before your expected withdrawal bleed?

I ask this because of the accuracy of hpts while on the pill. If breakthrough ovulation could occur at any time in a cycle, and if it occurs later in a cycle, would a pregnancy test still be accurate a few days after your expected withdrawal bleed?

Thank you!

[Heather]

If and when it did occur, which really isn't about "off-chances," it's almost always about people not using the pill correctly, there's no one time it'd be more or less likely to happen.

Pregnancy tests are accurate as described in their directions: that's usually if and when someone has missed a period or when it is late. If and when someone ovulated isn't a factor in the accuracy of pregnancy tests: they test for a hormone created by pregnancy, so it's a given that someone getting a positive has ovulated. Someone with a negative result may or may not have ovulated, but that doesn't matter, since they're not pregnant. Pregnancy tests test for pregnancy, not ovulation.

Make sense?

[honeybee12]

Yup that makes perfect sense! I was just wondering because if someone ovulated toward the end of an active pill pack the age of pregnancy probably wouldn't be old enough yet at the time of a missed withdrawal bleed. So in that case taking a test would most probably give a false negative, right? But you are saying that if a test is taken after the right time, let's say a week after a missed withdrawal bleed, that even though the withdrawal bleed isn't a true period, the test would be accurate then? There is a lot of vague stuff out there in the web about this sort of thing, but I trust the information from Scarleteen very much, so this would really clear things up for me.

Thanks!

[Heather]

Well, no, because while the timing between the start of someone's cycle and ovulation varies a lot, what doesn't tend to vary by more than a day or so, for everyone, is the timing from ovulation to a period. And someone is only going to miss a period or withdrawal bleed because of pregnancy when they are, in fact, pregnant. If someone misses a period or withdrawal bleed, then tests, and it's negative, it's because they aren't pregnant.

So, nope, again, none of this changes the accuracy of a test when someone has, in fact, missed a period or withdrawal bleed due to pregnancy.

[Heather]

It might also help to remember that the combined pill works in THREE ways: not only by suppressing ovulation, but also by thickening cervical mucus (which makes it so sperm cells don't have the kind of fluid they need to be motile) and by thinning the uterine lining.

So, even talking about pill failure as being about ovulation alone isn't sound: all THREE of these things would have to fail for a pregnancy to occur, not just one. And when people are actually using the pill properly, that's not likely. That said, it is easy to make mistakes with the pill, so if you're using the pill alone, and have worries like this, backing up with a second method is always a good idea, or you might consider a different method you feel better about and where it's much more difficult (if not impossible) to make user errors.

[honeybee12]

Okay, that helps a ton. So if someone did ovulate toward the end of their pill cycle and did not get pregnant because of the other two protective measures of the pill, they would still get a late withdrawal bleed, right? Because the number of sufficient days between ovulation and a period would need to pass, correct?

[Heather]

A withdrawal bleed, like a period, is the shedding of the uterine lining. That lining is where a fertilized egg implants, which is why when someone becomes pregnant, they miss a period or withdrawal bleed, because it's needed for a pregnancy to happen and continue. Again, this really isn't about days between ovulation and periods: it's about if someone became pregnant in their previous cycle or not.