TMI Pregnant?

me and my boyfriend were having sex 3 days after my period, we used water based lube and spermicide condoms to help just in case. some of his cum got around my vagina but I'm not entirely sure if it went in. I wiped It off right away and cleaned the area as best as I could, but I am still worried as I have a high chance of getting pregnant right now. I taking plan b later this afternoon. We had sex about 9:30 last night, so I'm taking it about 19 hours after having sex. would plan b be good to use? would it work since I'm at an easier time to get pregnant? am I just worrying too much?