3 months late on my period?

Haven't had my period for 3 months. Found out the last time i had sex and the condom broke was when i was ovulating...i had one very very short period the 27th of march which was late, im supposed to start around the 20th and haven't had one since. I haven't thought anything of it until recently i realized im 3 months late...although i haven't been feeling right, im constantly tired, i feel like im about to start my period but without the cramps but then never start. ive been peeing all the time. also my sense of smell is heightened and it makes me nauseous. But i took 2 tests, one the results never formed and the other was a very light colored minus sign, but didn't look as prominent as its supposed to look. Also i was talking to a friend who knows alot about pregnancy and there's weird little things, like my hair wont hold dye well, and im breaking out on spots on my face that never break out. And before all this i had been dieting, but after i moved back in febuary its been kinda hard to stay on it, kinda go on and off of it, and now it seems im loosing weight everywhere but my tummy