I was on azithromycin antibiotic... when I had unprotected sex... is the antibiotic going to have an effect on the birth control pill that I took

It may make the birth control less effective, also remember, the pill is not 100 percent effective when taken exact

It could have an effect. I would recommend having PROTECTED sex until the beginning of your next cycle. Might not have altered things enough to cause ovulation, but just to be safe. I am assuming you don't want to be a month because you are taking birth control.

Antibiotics do have an effect on the pill, and any doctor will tell you to use a back up form of birth control while taking antibiotics and the pill. You've definitely increased the chance of pregnancy by having unprotected sex during this time. You'll need to wait and see what happens with your next period.