My boyfriend and I had sex and it was our first time. He used a condom, but I didn't take a birth control pill. When we were groping each other, I felt his pre-cum. As he was putting on the condom, he put it on backward or the outside of it in. Then he put in on correctly. We had a great time, but when he popped my cherry he took it off. Then, he put himself inside of me but without putting another condom on. He said he wiped his pre-cum off. He went inside for a few seconds then he came out on my stomach. My question is can I get pregnant from what I described?
Any act of sex contains a possibility of pregnancy. Rolling five ones in a row with dice is rare, but not impossible.
A boy's pre-ejaculate fluid (pre-cum) can contain sperm. Usually not a large number, but it only takes one sperm reaching the egg to cause fertilization. A boy produces pre-cum constantly when aroused and that fluid drips from his penis. From your description, you had contact with his pre-cum during foreplay. He then got pre-cum on the outside of the condom, which went inside of you. He then put his penis in without a condom (wiping won't remove all the fluid or sperm) before finally ejaculating on you. While there may not have been a huge number of sperm present, the odds are not anywhere close to zero for you to get pregnant.
I can't help but notice that you apparently saw nothing wrong with what you and your boyfriend did. If you are worried about pregnancy, then I already know you are not ready to have a child; yet, once again, every act of sex contains a possibility of pregnancy. There is no guaranteed way to completely avoid pregnancy. However, what has happened is that you've sinned, which has graver consequences that mere pregnancy. "Marriage is to be held in honor among all, and the marriage bed is to be undefiled; for fornicators and adulterers God will judge" (Hebrews 13:4).