Well my boyfriend and I had unprotected sex 2 days ago, he didn't cum in me but he cummed on my vagina and it was my fertile days, is that a chance?

Age old question. Boys who have an erect penis leak semen before they ejaculate. Semen carries fresh sperm in it. It only takes on spam to make a baby and it is very well known that pre-cum in the situation you describe commonly causes pregnancy. The cum on the outside of the vagina is not the story here. The uncovered erect penis inside of the vagina is the real worry as far as pregnancy goes.