I had unprotected sex with my bf.but he felt when his cum was coming out.he took his penis out. all his sperm spilt in his hand. can i get pregnant?

It is possible: Depending on your ovulation cycle and the fertility strength of both of you, it is possible - not as likely as if he'd cum inside fully - but pre-cum has some sperm content. Since you are so young, it is always a good idea to use protection. Think of it as self-regard for both of you - it's a good habit to get into and shows each other that you care.

Pre-cum: Yes. Absolutely. Any uncovered erect penis is leaking semen, which has fresh sperm. Even if there was withdrawal there is risk. 30% of couples who do just as you did get pregnant. Pre-cum leaking from the penis has the same concentration of sperm in it as a the full ejaculation does. Any penis inside of you must be covered with a condom to prevent pregnancy or you must be on birth control.

Yes, definitely: If you want to avoid pregnancy, then the pull out method or withdrawal, isn't your best option. Use a condom, or even better, birth control and condoms to prevent pregnancy.