Pregnancy?

Hey ladies. So I had unprotected sex with my boyfriend (bad idea, I know and regret it. It was in the moment. Still not an excuse.) he didn’t ejaculate at all and currently I’m in my fertile period of my cycle so I had about a 10% chance of pregnancy that day I believe. I know precum does have a slight chance of getting one pregnant. I’m 17 and I can afford Plan B if it’s absolutely necessary. Any advice, tips or information? Thank you.