I'm Scared I May Be Pregnant.

My boyfriend and I started having unprotected sex about 2 weeks ago. He always pulls out but I know pulling out isn't a guarantee I won't become pregnant because of pre ejacculation. Maybe it's too early & maybe I should wait to see if my period comes on in the next day or two. I've been cramping for the past day & some discharge. Nothing abnormal. That happens every time I'm about to have my period.