How does the pill prevent pregnancy?

[FadedPassion]

Hello!
I have anxiety so sometimes I get anxious if my pill is working correctly. Im now wanting to gain more education on the topic so that I can feel more comfortable and I hope you can point me in the right direction.

I'm on Ortho Tri-Cyclen birth pills for 9 months. I get breakthrough bleeding/spotting every month in my last week of active pills. I've been told that this is a common side effect and that my lining just isn't being stabilized enough which is why I'm probably bleeding a bit but that I'm still fully protected.
My question Is, if that's happening to me then I would think that it's possible that the pill isn't working properly in preventing pregnancy in other ways such as stopping ovulation etc? I was told I'm wrong about this but I was wondering if I could have more in depth insight or even an article explaining it to me. I really appreciate It!

[Mo]

We do have an article about this! How do birth control pills really work, even during the placebo period?

[FadedPassion]

Wow that's a great article. I really appreciate it! I want to read it again to understand better. Sorry for this dumb question but I think it's why I'm still a bit confused. If one way the pill works is by thickening my uterine lining, but I spot every month so doesn't that mean the lining isn't stabilizing properly? If that's the case then isn't it possible that it's not doing those other things to prevent pregnancy? Or am I totally off? Lol

[Mo]

Nope, that spotting doesn't mean that there's a problem with your pill. As you noted above, it's a common side effect, but it has nothing to do with the pill's effectiveness.

[FadedPassion]

Okay. My apologies if I sound repetitive. The spotting is caused by the unstabilized uterine lining right? If the uterine lining is not being stabilized then wouldn't that make the pill less effective (since that's one of the ways it's preventing pregnancy).
I'm sorry if I'm not understanding this properly.

[Karyn]

I'm not sure what you mean by the uterine lining being "unstabilized" - that's not a term I've ever run across before. Could you explain a bit more? (It could be that we're thinking of the same thing and just using different language to describe it!)

[FadedPassion]

No worries I'm sorry if I'm not explaining myself clearly. Let me try again.
I read online that one way the pill works to prevent pregnancy is to support the uterine lining (endometrium) to prevent breakthrough bleeding and that it also makes the uterine lining inhospitable to a fertilized egg.
Now I was told by someone that if I'm spotting then that means the uterine lining isn't being stabilized properly but that it has no effect in lowering my protection against pregnancy. I'm confused at how this is true. If my uterine lining isn't stabilized, and that's one of the ways in preventing pregnancy then wouldn't my protection be compromised?
I'm just confused about how that all works.

[Karyn]

Thanks for elaborating on that, I think I get where you're coming from now.

So, the pill works by sending different hormonal signals to your brain, ovaries, and uterus, with the overall effects that the uterine lining is thinned out/doesn't build up as much, ovulation doesn't happen, and cervical mucus is thickened so that sperm have a harder time making it up into the uterus and fallopian tubes. Maybe what this person meant when they said the uterine lining was stablized was that it was thinner than it would otherwise be, but that doesn't necessarily mean that breakthrough bleeding won't happen: your body is still producing its own hormones, and there can be small fluctuations in hormone levels - due to a bunch of things - that can trigger some bleeding. (Spotting/irregular bleeding is actually a pretty common side effect of the pill.) It doesn't have anything to do with the uterine lining not being "stable", and it doesn't mean that your pill isn't working, because bleeding isn't an indication that the pill isn't doing what it's supposed to.

Does that make more sense?

[FadedPassion]

Ohhhhhh okay that makes a lot more sense. So if the pill is meant to make your uterine lining thinner, yet I spot every month, wouldn't that mean that my uterine lining is actually thicker than it should be? I could be totally off on this but that's just how my mind is trying to make sense of it lol.

[Karyn]

Not really: bleeding doesn't happen because there's "too much" uterine lining, it happens because there's a slight change in hormone levels. (For example, some folks are more sensitive to those fluctuations and find that they have some spotting or bleeding if they take a pill slightly late.)

[FadedPassion]

Ohhh okay I understand better now! I just don't really get what could be going on with my body then because I take my pill religiously at the same time everyday in only ever late by maybe 5 minutes but I know that wouldn't do anything.

[Karyn]

I should have been clearer, sorry. Taking a pill a bit late is just one possible cause of the slight hormone fluctuations that can cause spotting. Your body still makes its own hormones when you're on the pill and small changes in those levels (which happen for a bunch of reasons) can cause some irregular bleeding too. Bodies are complicated things, there are a lot of chemical and physical components all interacting and sometimes they just don't do exactly what you expect them to.

[FadedPassion]

Oh okay. Thanks for clarifying.
One thing I was just thinking about is that I'm on a Triphasic pill so I'm getting a different dosage every week. That would mean I'm getting a fluctuation of hormones every week. Would that make sense to why I'm probably experiencing this every month?

[Sam W]

That's really not something we can say for certain. Like Karyn said above, there are a ton of chemical and physical components interacting in our bodies, so it can be difficult to pinpoint the exact cause of something like spotting.

[FadedPassion]

Sorry for posting 1 more question but I was curious about something I read online. I read that during your break week your uterine lining is no longer being "built up" since you get your withdrawal bleed because the hormone levels drop. Is this true? If that is the case then how are we still 99.7% protected during the break week?

[Karyn]

Yep, the drop in hormones during the placebo week is what tells your body to start the withdrawal bleed. The piece that Mo linked you to in his first post explains in more detail why you're still protected during that week, but basically it's because of all the things the pill has done in the previous three weeks and will do again once you start your next pack of active pills. Have a read of that piece, and if there's anything that still isn't clear, let us know.

I also wanted to ask - since it seems like you're stressing about this a bit - if the pill is a method you feel comfortable using, something you trust to work?

[FadedPassion]

Thank you. Yes I want to read that article again it was very helpful and I want to thank you for being so helpful!
I used to be quite anxious about my pill but the last few months I've been a lot more comfortable and I trust it. The only thing that makes me feel uncomfortable now is having sex during the break week. I know you're protected but I guess not taking the pills during that time makes me a little scared that the hormones would drop enough to possibly start ovulation. I had sex on my 2nd sugar pill of this pack and I got my withdrawal bleed on my 4th sugar pill which I normally do. I've always taken my pills on time but it just worried me a bit because this is my first time having sex on the placebo pill week. And now I've been getting major hot flashes with this period. I feel like I'm always hot and burning up and someone told me that your body can feel like that when you ovulate. I'm most likely just overreacting, Haha! But you all make me feel more comfortable.

[Mo]

Keep in mind that the birth control pill has been set up this way, with the placebo week, for decades now - we'd know if the pill was less effective then! If you feel uncomfortable having sex during this week, even so, it sounds like adding condoms would be helpful, if you aren't doing so already, so you can have extra protection and extra peace of mind (in fact, we do recommend this for all pill users, especially those who worry about its effectiveness).

[FadedPassion]

Thank you. Yes I do agree that for future break weeks that it would be a good idea to add condoms. The rest of the active pills it doesn't bother me. I think I was so anxious because it was my first time not including condoms during the break week.
Is it a common side effect to feel extremely hot during your withdrawal bleed?