I think I was in the second week of my birth control pack when I was out of town and lost it. The last night I took it was either Thursday or Friday. I had unprotected sex on Wednesday night and Thursday morning. Then again on Sunday night, and this time he finished in me. We had sex again in the morning but then my period started. It lasted until Weds or Thurs and I started a new pack on Sunday.
Am I safe? Or is there a possibility I'm pregnant?

Or is there a possibility I'm pregnant?

ANY time there is penile insertion there is a possibility of pregnancy. You can reduce the possibility by using birth control properly, but not eliminate it.

The fact that you had a period after the intercourse makes the possibility of pregnancy rather small, but since the period was so close it doesn't eliminate it. You will have to wait until your next period is due to be sure.