No period!! I am getting worried!

April
My last period was Jan 14! I have been taken test after test and they are coming up negative... I talked to my OBG Doctor and she is asking me about my thyriod. I told her I think I need a check up! I never been this late before! Well neatless to say she called me some medicine to make me start. I took the 10 day pills since last week! I took the last one 3 days ago. And no period!! What is wrong with me???? And I am 32 years old!