Am I pregnant?? (sorry ik its a super faq here ;-;)

Yes we had anal sex unprotected. no condoms. I heard that its impossible for pre cum to make you pregnant unless a man ejaculated earlier before sex because the sperm from the last ejaculation goes through with the pre cum too. He did not ejaculate the day we had sex, we only had anal, he just penetrated my vagina with three thrusts accidentally, which caused met to bleed for a bit. This day is the 18th day from my last period.

I cant easily get plan B because im 16. Im sorry, i know protection is a must. I was wondering if there are clinics that do give the pills minorities.