pain in my left hamstring
 

I stopped taking dance about 3 years ago, but post-workout I do all the stretches my teacher had me do before to maintain my flexibility. She would have me do a bunch of stretches, then have me do all the splits(right, left, and in the middle) and lower my upper body to the floor and hold it for a few seconds. The other day, I did the middle splits, then the one with my right leg in front, but when I went down into the left split, I felt a pain in my left hamstring like I was stretching it too much. My muscles are always warmed up before I do any stretches, and I've never felt any discomfort while doing them. That's why I don't know what's wrong. My question is, do I just gently stretch it and wait for the pain to eventually go away or is there anything that can heal this faster?