I agree with maleficent could be endometriosis. Often it's simply treated with birth control. It probably wouldn't hurt to call your Dr. and let them know the symptoms you are having. They may want to see you sooner than your appointment date. I don't know how "serious" they consider endometriosis. But it does need to be treated so do talk to your Dr.
I don't want to scare you though. It could just be that you are young and your hormones are still a little wacky. But it's always good to talk to your Dr. just in case
