Help!! I may get pregnant?!

So I normally have a hard time taking my birth control on time, the week before my period I took it on time everyday, and then I had my period. At the very end of my period week me and my boyfriend where having sex with a condom and when he came and pulled his dick out, his dick slipped out of the condom and the condom was still slightly sticking out of my vagina and the cum was spilling out onto the sides of my vagina. I'm really scared that somehow I could get pregnant from this! Should I take the Plan B pill or not? :( please help!! There's still time for me to take it