How do i know if he nutted in me?

I have the mirena iud btw. So me and my boyfriend had sex and he says he pulled out but then i went to the restroom to pee and when i went to whip i was dripping clear discharge and a little bit of it was milky white. i’m not sure if that’s normal after having sex? like was it my cum or was that his nut? any opinions? i’m new to this whole sex thing.

Update: i bought a plan b