hi, my name is Katie. im 15 years old and im freaking out. I had sex 2 weeks after my last prd which was October 17th of 2013. ive taken about 4 tests and they've all been negative? now its been 2 months since my last period. I haven't had any signs of pregnancy. and when its around the time im supposed to have my prd I have all the symptoms. cramps, migraines, nausea, bloating, moodiness, and sleepiness. but nothing ever comes out. I haven't spotted or nothing. just no period. no signs or nothing. I don't know what it could possibly be. help me doc?