Blood

I had unprotected sex 2 days after my period about 2 weeks ago (I don't remember any of it, I was drunk and on the xans). I regret it so much and I'm so scared I'm pregnant. According to this app, my fertile window just ended. I have some blood coming out of me that sorta looks like the start of a period but I'm not supposed to get my period for 2 weeks. It's always been irregular but it is usually always late. Does this mean I'm probably pregnant or is it just my period coming really early? Please give good advice as to what I should do. I know that any time you have sex there's a chance of pregnancy I just need help easing my nerves please