What Causes Nausea, Breast Heaviness And Cramps Despite Having Negative UPT?

My basal body temp. is 99.9, the past two weeks I wake up soaked in between my thighs and lower back. I am on day 46 today of my cycle and still no period. Today I got a negative home preg. test but Im not convinced. I feel like my period is coming but it's felt like that the past three weeks. I am over emotional, nausea, tender fuller breasts, bloated comes and goes but for the most part always feeling cramps and tight uterus. I feel starving even still after I eat, major exhaustion more than like before your period. Hot flashes like crazy and my face hasnt broken out yet which hasnt happened in the last year ever. Feeling of UTI sometimes too and I have had this head cold for a month now, so much snot and mucus still not all the way gone yet. My cervix is still high, soft, and always extra wet lately. I am 21 and not convinced that I am not pregnant right now? please help