Should I be worried?

I am 12 days late for my period and my period does get late on the regular, ranging of a cycle of 28-50 days and averaging 34 days.

My boyfriend and I had unprotected sex on my last day of my period. He didn’t finish whatsoever and pulled out far from finishing.

I took doxycycline hyclate on the third day my period was late. I’m not sure if it’s the reason why it’s delaying it.

If I were pregnant, I’d be over 5 weeks and I haven’t felt anything at all.

I’m not sure if I should be worried but some advice would really help. I’m just worried sick.