Yellowish-green discharge is not a good thing. I imagine that if you aren't sexually active then you won't have a Gynecologist. The first thing you need to do is talk to your mom (even though you may not want to). She has to know what is going on with you so she can get you in to see a doctor. If you have not been sexually active then you have minimal worries, if you have and it was unprotected sex then it may be an STD. Even though you may be embarrased and even scared, you can't let this keep going on; if it is an STD then it needs to be taken care of immediately. STD's can cause you to go blind, lose your chance to have children when you are older, and even cause death if they go untreated. If you decide not to talk to your mother then you need to find the nearest planned parenthood, so you can have a pap-smear and be checked out for any problems. They won't tell your parents. If you don't have one in your area then the only thing left to do is talk to your mother, don't be afraid to talk to her. Good luck sweetheart.