What Causes Delayed Period, Drowsiness And Breathlessness While UPT Is Negative?

sir, this is the first month when i did not have periods, and then tested negative in pregnancy also ...then Doctor suggested me to take primolut-N..for 5 days , thrice a day....even after completion of the course..i am not feeling welling,,always feeling pukish, sleepy, and not feel like having food, week, short breathe....kindly suggest..