plan b

sooo i had sex with my boyfriend and i was riding him and he felt that he was about to cum so i got off he checked and there was nothing but pre cum so i went back to riding him and then he cummed a min later on his hand. We took a break and started going at it again he ended up finishing on top of me the 2nd time, i sucked his dick for a bit and then he started fucking me again , 15 mins later we bought plan b. but would the pill be effective enough for that?