Help! I think im pregnant, but everything's coming up negative!

Okay, so this is kind of a long story, I'll try to make it as short and simple as possible.

Last Wednesday I realized that I was 3-4 days late for my period. I didn't think too much of it, but a part of me started to worry. My fiance and I are regular condom users, and we've been in the clear for over a year and a half.

However this time around I noticed that I was acting slightly different. (before I realized I was late) I noticed that I was extremely moody, which isn't that off for my menstrual cycle, but this time it was really odd. I was being really impatient with my fiance, and acting very cranky which is really unlike me. We got into our first fight during this period of time, and after I realized I was late I felt really bad for being so cruel to him.

Another thing, I got sore throat Friday, and it's still hanging around right now. This is weird because normally when I get a sore throat I get SUPER sick. My immune system isn't usually kind to me, and I usually get flu like symptoms the evening of my sore throat discovery.

My eating habits have also been weird, like I complain that I'm super hungry, I eat, and I'm good. But last night I was craving chili, so I made some up. Why is that weird?? After I ate a couple bites I was feeling kind of gross. Like kind of nauseous, gassy, and like heartburn was coming. I was also having coughing fits the whole night. The whole chili situation is not normal for me. I LOVE chili, and normally I can eat two bowls before I call it quits.

I've taken three tests in this week time span, and they've all come up negative. But my period is still not here, I'm feeling a little nauceous, and my throat still feels off, and I've had to pee like every hour.

I really am not sure what to do, I work a retail job so getting time off is almost impossible for me. I've done all kinds of research, but everything I've read has had to do with women who were trying. I haven't seen much of the accident stories. I just want advice, and I want to hear if someone's had a similar story to mine. I just need to know if I'm overreacting or not.