4th placebo pill no period

I took one of my acne meds minocycline which is an antibiotic several weeks ago had sex that weekend. We started without a condom for the first few minutes but put one on after, no leaks and no leaks from the last time we did either. I’ve never missed a pill, I’ve had to take it an hour early at times for Band. Can I be pregnant or am I just stressing myself out?