PLS HELP! TROUBLE WITH CONDOM

So my boyfriend and I just had sex WITH a condom. I am on my 4th fertile day and kind of worried that I might get pregnant. Anyways my boyfriend and I were fucking and he finished inside me with the comdom on and then pulled out. I know that the condom didn't break or anything but I had a lot of cum on me. Idk if it was mine or his. All his cum was in the tip of the condom, but then there was some cum like on the side bottom part of the condom. So basically I'm wondering if my cum could possibly get up into the condom while having sex??? Pls help, I need to know asap if I should get plan B 
UPDATE: just to clarify, his cum was in the tip, and there was cum in the side of the condom as well that was leaking out. And idk if it was mine or his. That's why I was asking if my cum can get inside the bottom/side of the condom