Last Week A Friend Asked Me If I Could Do

Last week a friend asked me if i could do the splits, so i got down and did it right away. I went down very fast without stretching. As i was going down i heard three pops/crackling noises and i could feel that something was wrong right away. I had troubles walking for a few days and now it hurts randomly, when i tense up my leg and when i stretch my hamstring just the lightest. Also, starting this week the muscle will randomly tense up and get really tight. Whats going on? did i tear something?