Came ON me not IN me, took plan B but my weight..

Hello! My and my boyfriend had sex like around 6:20pm and he did pull out but he aimed downwards and it hit my vagina, like underneath the hole. We immediately ran for Plan B 10-15 minutes after. I was supposed to start my period this week but I highly doubt due to Plan B.

I also heard that Plan B is less effective on women who weighs more than 165-175lbs. I currently weigh 172. I don't know if it is because we had K-BBQ today kr I just gained weight. Any opinions or thoughts? Would greatly appreciate it!