I have a general question. I did call my doctor, but I then had dinner with a friend last night and she made me a bit paranoid lol.

I started an antibiotic for a vaginal bacterial infection on Sunday afternoon. I take Ortho-Tri-Cyclen Lo... When I first received the antibiotic from my dr. I asked if it makes the birth control pill less effective and she said no. So, Monday, I had sex. After sex I was so bloated and crampy and got my period. I now have my period. I called my dr. and they said that I should be OK because I'm on my period now and even though I'm early with the pill, to continue taking the pills like I normally would. What made me paranoid is that my girlfriend said that even if I had sex one day, I could get pregnant...

I guess I'm just looking for someone to calm my nerves. I have a rough time explaining myself on here, so if you have a question, please ask.

Hi there,

OK first of all I don't think you should be having sex when you have a bacterial infection not until its cleared up, and secondally yes of course you can get pregnant from having sex just one time but if you have your period now then I wouldn't worry I would double check to make sure that the antibiotic does not interfere with the pill for the future but for now I think you should be fine stop worring! :)

Do antibiotics make birth control pills less effective?
Early data about 20 years ago seemed to indicate that when antibiotics were taken along with birth control pills, more women got pregnant than you would normally expect. Drugs like ampicillin and tetracycline were suspected to interfere with OCPs (3). However, all of the recent studies that have looked at this, have shown that antibiotics do not increase the pregnancy rate at all (4) and they point out that the old data was not reliable enough to draw conclusions about pregnancy rates on any of the antibiotics (5).

Some antibiotics have been studied and shown not to affect the metabolism of OCPs. Ciprofloxcin (Cipro ®) is one that does not seem to alter metabolism (6). Fluconazole (Diflucan ®) does not decrease estrogen levels in pill users; if anything, it raises estrogen levels (7).


Source: Find Out Which Drugs Can Affect Your Birth Control Pills

Well my Dr. told me it was OK with the antibiotic... but I happened to look it up online and it said that it does interfere with the pill. My gyno also said that getting my period early on the antibiotic is normal.. just a way of my body reacting.. and to continue taking the pill as normal... but I still worry because I had sex on the anitbiotic once, thinking it was OK... and now I'm paranoid lol.. but have my period lol

The drug I am taking is Metronizole or something like that.

If both of your doctors said it was OK, it probably is. Problem with the internet is there is a lot of speculation, and you can't believe everything you read. If you are still worried, you can always use a back-up method.

If you have a vaginal bacterial infection and have sex with a partner you can actually infect the other person. It is quite commong for women to have a bacterial infection treated and cleared up only to be re-infected by their partner.

You can still get bleeding even if you are pregnant.

Handy info h_leann_b I'm pretty cautious though so I never have unprotected sex while taking antibiotics, rumour or not, I'd sill worry about it! :)

Ya, from here on out, I would say use a back-up method while taking your pill if you start an antibiotic.

As an update to my post here. I had my period and still have spotting. My period wasn't a bright red color, but more like brown and lasted over a week. I got my period early from the antibiotic and while still being on my last week of my birth control pill cycle. This is the week I should be getting my period now and I feel somewhat crampy although I just had a "period". My dr. said the early period from the meds is normal and I shouldn't worry but I tend to get paranoid. Anything like this happen to anyone else?