Condoms, Urgent!

I'm sorry this might be a little personal for you all...

But I had sex with my boyfriend today and we used a condom as protection, the condom was all good no holes or tears. Although there was a lot of wet stuff all over the condom (and I know there is lube on them, and also my wet stuff)

However this wet stuff was at the very end of the shaft of his penis like where the condom ends. So I'm wondering could the condom of moved and his precum have slipped out into my body, or is it not a big deal? Keep in mind the condom was a perfect fit.

Therefore is it worth purchasing plan B to be on the safe side?