I need help

Ok so my bf and i did it on Nov 9 and i had gotten my period two weeks before so i was on my fertile window when we did it. He pulled out but im worried about the precum?? And a few days after we did i started to get cramps and my boobs started hurting. I took a preg test this Friday and it came out negative and supposably i get my next period in 7 days. Is it possible that i can be preg?