So today I started doing Tae-Bo after taking a break for the last two weeks. I did fine and finished my session but I noticed every time I had to lift and kick, or squat or lunge my knee was cracking, kind of sounded like I had foil in my knee. It didn't hurt and it isn't swollen at all. Should I consider going to the doctor? I don't want to go and just be told it's ligaments or air.