I just had my first time I need help

I just had my first time yesterday... I know it's bad to have unprotected sex but it kinda just happened. On Thursday at like 5 pm .. I start ovulation on Monday... I have till Sunday to take the plan b pill... we did the pull out method but like it was my first time and I told him I'm on nothing so he decided to do anal too so it was regular then waited a while and we did it again but it was anal then regular I think ...

My friend said there's a 2% chance precum will get you prego but is that actually true ? What's the percentage? Do u think I should get plan B or is it not worth it ?