Positive pregnancy test but not sure

I took a pregnancy test today, and it came out positive. The night that would have made it possible to be pregnant was July 4, I am on birth control and used protection but I was also on a strong antibiotic. Is it possible to get a positive so early or could it have been a false positive or could it not be ?

It is possible to get a positive already. Did you take another test after just to be sure? False positives are pretty rare so I would say you are probably pregnant.