My doc put me on metformin and something for my thyroid as well. I've lost about 16 pounds so far. It's known that women losing weight tend to somehow kick things into gear and can suddenly get pregnant. I asked the pharmacist if I would need to worry about this even though I'm on the pill, and he said no that the pill should take care of it.
However, my doctor said he's seen three women in his program before who used birth control that have still wound up pregnant.

Can anyone explain this to me? Is it the metformin? Or any idea on the likelihood of this occurring?

I've only been in the program for a month and a half, and already my period has been messed up. Halfway through my pills I went on an unscheduled period and then when it was supposed to show up last week, it only lasted maybe 3 days and was super light. Should I be very worried??

Edit: Sorry, I should've said I haven't just started birth control pills. I've been on them for over a year, and I never miss a pill. But what my doctor said makes me nervous anyway.

What TYPE of birth control and are they using correctly? That's the key.

If you are not wanting to be pregnant and just started a pack of birth control pills and aren't sure -- trying charting and condoms as well to be sure. I had some breakthru bleeding when starting packs -- it settled down in subsequent packs but to be sure we also used condoms at that time.

HTH
A.

My doctor told me a while ago that metformin can make you more fertile, so it is a possibility. Though, if you're on the pill, then I'm sure you should be fine. He put me on both, just in case (since I wasn't looking to bear children).

Metformin does make you more fertile if you have PCOS. Thats how I got preggo with DD2 after trying for 18 months.