Can Having Unprotected Sex While On Pill Cause Pregnancy?

Hi there, im on the pill and I take it seriously every day. I've been on the pill for about 2 years now. My boyfriend and I had sex last night( with protection as well) the condom had spermicide in it . We went to roll over and he slipped out ( he already ejaculated before the slip) and as he was adjusting him self the condom slipped off and the ejaculation went underneath me as I was laying next to him, he was not inside me when this happened but it spilt under my butt, but was close to my vagina as well as soon as I felt it go
Under me I got up and went to wash it off. Taken, the sperm hit my sheets before me. I've researched that plan B won't really help if I'm already on the pill so i think I'm okay and just over thinking??