I popped my knee what should i do?

i was skateboarding at a skatepark and when i came down a ramp my leg slipped and kinda did a split.my knee had popped at first i could not breath but the pain kinda went away so i started skateboarding i little bit doing alloys over the things and i walking around the mall and other places and i was fine but now that i fell asleep i wake up with a pain that makes me want to yelli cant walk or move my let should see a docter?