Hey, I Have A Question. My Boyfriend And I Had

Hey, I have a question. My boyfriend and I had sex last month, we used protection but it was questionable. A couple of days later I got period on the day that I should get. It lasted 7 whole days though I didn't get cramps, I only got headaches. Now today I should've got my period but I didn't. I have all symptoms of PMS. Is it even possible to get pregnant even though I got my period after sex?