Wont start Period and not pregnant..

Patient: I have missed my period for almost four months..I did have spotting about a month ago but i dont know if it was my period or not. I have anxiety problems and irregular periods. I’ve never gone this long without a period. I’m sixteen and i am sexually active. I know I’m not pregnant because I’ve taken two tests. I had sex three days ago and we used a condom. The last two days I’ve had a urge to urinate so I’ll go to the bathroom but then i feel like i have to go again and only a little comes out. Is there something seriously wrong with me? I dont want my mom to know I’m sexually active..so i don’t want to go to the doctor if there’s nothing wrong..

Doctor: