Should The Swelling Around Knees And Thigh After An Injury Cause Worry?

Hello I was skating yesterday when I came to a standstill to talk to my brothers. I started to go backwards not loosing much balance but then all of the sudden I felt the right side of my right knee pop and I went straight down with my leg bent underneath the other one. The pain was excruciating and I laid down for a few minutes before a few guys helped me get up and get me off the ice. I cannot put any pressure on the knee whatsoever as far as standing or walking. I can move my knee every which way except for full extension. There isn't noticeable swelling but there is pain on my right knee and thigh. When I am sitting down there is not much pain but when I try to stand it feels like i have needles zinging through my bones.