p90x knees

When I workout my knee makes a popping/snapping sound. It doesn’t hurt so should I ignore it?
I am trying to do the P90x, however when I do squats or lunges my knee makes a slight pop/snap sound every time! It doesn’t hurt, and I really want to keep going but I don’t want to mess anything up in my body. I don’t have health insurance to see a doctor about it, nor do I have a gym membership. I don’t know what to do.
Check this product out… I buy stuff from this website all the time and they are great. They have fast shipping and pretty cheap prices. This might help with with your knees.
http://www.bodybuilding.com/store/univ/flex.html
P90X Day 38, Plyo: Jump Knee Tucks and Mary Katherine’s