Hii so my bf came over saturday/sunday and we wanted to try something and stupidly i let him put the tip in but itd barely go in later on i got worried cause i heard theres a possibility precum could get you pregnant so i took a plan b and idk?

Pre-ejaculation semen contains some sperm. "Plan B' is not 100% protective against pregnancy. If your normal cycle is delayed, obtain a serum HCG test to be certain. See your GYN physician and ask about low dose oral bcp's.

The risk of pregnancy is less than minimal. If you miss your period by more than 4-5 days, do a home pregnancy test. If the result is negative, repeat it in 4-5 days, unless you get a period by then. If you do not wish to be pregnant, use contraception all the time, every time. You may consider implanted contraceptive, or IUD. Get HPV vaccine.

Repeated studies have shown that precum has no sperms. So unless there was ejaculation inside your vagina you cant be pregnant.