Advice please! Urgent!

Tomorrow I will be 28 weeks. About two days ago I was sitting in the floor playing uno with my family. We have a pretty large boxer. He accidentally stepped on my pelvic area. It hurt but the pain went away after a few minutes. Well after I went to bed I woke up with horrible pains. My vagina area was swollen and I couldn't pee. Finally I could and the swelling went down. The pain got worse. Well I thought it'd go away. Now, any type of movements hurt that involves my legs or quick movements. The pain is going up into my belly. Swelling has came back and I have some clear fluid leaking. I am on my way to the hospital but was wondering what any thought it could be?