Birth Control and Antibiotics

[raily_]

So this is a long story but bear with me, I have had some tooth pain for about a week now. I called the dentist today and they said it could either be my wisdom teeth or a tooth infection. He prescribed me some antibiotics (Amoxicillin) to take for a week. I know some antibiotics can mess with birth control so I googled and although Google says Amoxicillin won't mess with my birth control I still called my primary doctor to ask. They told me that it was really a 50/50 chance it might mess with it and that I needed to either be abstinent or very very careful.

Unknowing that I would be put on antibiotics, I had sex last night. Three times but he did use a condom. If I start taking the antibiotics and it lessens the effectiveness of my birth control, am I at a really high risk of getting pregnant?

Every single time we have sex, he always withdraws before finishing and makes sure to hold the base of the condom so it doesn't slip, except last night the first time he did not hold it (trust me I scolded him) and when I looked down you could see the condom had slipped down his penis a bit. It was not off by any means but it did slip down. He immediately went to the bathroom to check for holes or any leaks and he said there were no leaks, not even around the ring of the condom where some could have spilled out. And when I looked at the bed you could see a spot on the bed, we are pretty sure that the wet spot was from me, but it just happened to be the same time the condom slipped down. Basically, I am asking: If I had sex last night and start my antibiotics today, (worst case scenario) could I get pregnant?

[Sam W]

Hi raily_

So, if you start your antibiotics today, you won't have a risk of pregnancy, in a large part because you were already protected from using condoms and withdrawal. With that particular antibiotic, here's what we know: Current research indicates that common antibiotics such as amoxicillin have no effect on the efficacy of hormonal birth control. However, much of this research has included sample sizes considered too small to detect a rare interaction that may occur in less than 1% of users. So if you are taking an antibiotic, your decision to take more precautions depends on how much risk you are or are not comfortable with.

Too, so you know, in order for a condom to fail it has to break or come off all the way, rather than slipping a little.

[raily_]

I have still been sexually active after using amoxicillin. I later did some research too, so I could read more about it, and really all I could find was that the only reason Amoxicillin would make your OCP less effective is that with some people, it upsets your stomach (causing you to throw up the OCP you just took). I have not experienced that in my case, does that mean I am still okay? I have been paying close attention and it has not felt like my birth control has done me differently (EX: not working as well and causing me to ovulate).
Do I have anything to worry about in regard to (serious) risks of pregnancy? We have still been using condoms and he has been using the withdrawal method too.

[Nicole]

Hi raily_,

Based on what you've told us, I think you should be okay, pregnancy risk-wise. You took precautions and used barriers correctly, so there is a high chance you will not get pregnant. With that being said, I would continue to use condoms just to play it safe. Also, I feel like it will relieve a lot of anxiety, especially since the research on antibiotics impacting birth control efficacy is limited and your physician said there's a 50/50 chance of interference.