Ouch, Ouch, Ouch. Leg cramps and Synthroid

So I am a college tennis player. I have been on Synthroid for about 4 months now. I wasn't playing tennis when I first got on it, but now I am. I can't seem to make the calf muscles stop cramping. It's pretty frustrating and effects my game.

Is this something that commonly occurs with the hypothyroidism itself or is it caused from the Synthroid? I need to find some relief, but don't know which direction to turn. I don't think it is caused by dehydration or the other normal causes, because I have never had this problem and I am doing the same things I have always done.