Kinda worried, a little tmi but need advice

I started the birth control pill almost 5 months ago, I just got put on a new birth control not even a month ago (like a little over 3 weeks). I was not sexually active when it got switched, then I had sex twice... and didn’t he didn’t use a condom. The first time he didn’t finish but there was pre cum and the second time about a week ago he did finish. I was supposed to start my period 3 days ago (the last row of white pills started 3 days ago) and I’m a little worried I might be pregnant.. there is a slim chance because of the pill (9% chance) but there is still a chance. Do any of you ladies have anything honest to say to let me know the possibility