Pregnant?

Around 2 weeks ago, my boyfriend and I had unprotected sex and he pulled out when he was finished but said that there was some that might've slipped out. Now I feel sick all the time, my boobs hurt, I'm bloated, and my stomach won't stop cramping. I can't go to the doctor because I'm still in high school and don't want my parents finding out. Should I buy a pregnancy test and do it now or wait another week?