Possibly pregnant?

My name is Talisa, I’m 16 yrs old. My boyfriend and I have been together for almost 4 years. We found out this past June I was pregnant, by the time I was 8 weeks along, I had lost the baby. And a week and a half before my last period we had unprotected sex, and my period wasn’t it’s usual, it lasted maybe 1 1/2 to 2 days and it wasn’t as heavy. I had some cramping and light spotting (which I had in June), my back has been aching in the lower part, my food doesn’t seem to agree with me, I have headaches, my boobs hurts badly, I have been running to the bathroom every 1-2 hours. It all sounds like I am pregnant. But I don’t know if it is even possible to get pregnant a week before your period! Any thoughts/ideas?