I haven't gotten my period for 4 months. I'm positive I'm not pregnant and I don't smoke or do drugs or do anything that would interfere with my period. Is this serious enough to go to the doctor or should I just continue to wait.

Anytime you miss your period for an extended length of time, without pregnancy, you should see your doctor. There are a number of things that could be wrong, some that are not at all dangerous, but others that are. The early you find out what's going on, the better.

Good luck.