Physician stressing me out

I am planning to get sexually active and went to see my college’s physician to get birth control. While we were talking, the physician said that I can get pregnant from genital rubbing because there is precum. I am a virgin but have done stuff like oral and rubbing. There was one recent incident that really freaked me out: I was sitting on my bf’s belly and he ejaculated, and it landed on my butt and kinda dripped down to my vagina opening. I cleaned everything up right away, but what the physician told me stresses me out. Any advice?