can you get pregnant if you're on your period?

I had sex on the third day of my period and we didn't use a condom or anything like that. I cleaned off his pre-cum a little before but is it possible for me to get pregnant from his pre-cum? To be clear, he didn't cum inside of me. He only thrusted a few times before I made him stop. I'm only 16... and I really don't have anyone to help me with this and my family is super against sex as a teenager because my mom was 16 and pregnant. My period is over now but I don't want to wait until next month for my period to come again to find out if I'm pregnant or not. I just really want to be sure. Any advice or help?