Go to your doctor. I'm not sure what country you are in, but generally any visit to your doctor is confidential, so your parents would not know.

Or you can go to planned parenthood clinic.

Either way you need to see a doctor (your own or one at a clinic). Since you are sexually active you need to be having annual pap smears/physical exams. If you are old enough to be having sex you are old enough to take responsibility for caring for your health.

also didnt you say you had a miscariage on another forum? then you really should go and get checked out....