HELP!?!

Chey
My last period was 42 days ago and I still haven't had my next period. I took a Rexall brand pregnancy test and it said negative. I have one more ill be taking in the morning first thing..... Me and my boyfriend haven't had sex in over a month since he left for work which is 12hrs away... I'm getting headaches like crazy, stomach pains, I cant eat some foods that I like, feeling tired a lot more than usual, and don't really feel the urge to do ANYTHING..... Help?