First time taking plan b

Hi 19F, first time having to take a plan B. Me and my bf were just being so dumb and went unprotected but he pulled out a min before he finished. After 10-15 min we started having sex again after he’d already finished but he didn’t urinate after the first time he finished so I’m worried about leftover sperm and whatnot, but he cleaned him with a towel.

My last period was July 20-July 24, and my Flo app said my ovulation week was July 29-Aug 4, (predicted ovulation to happen on the 2nd). We had sex last night August 7.

I’m really worried about taking a Plan B and the side effects. Should I be worried in my case at all about pregnancy??