2 negative pregnancy tests, am I pregnant?

I'm now 2 months late for my period. In the last 2 months I've had a few bouts of nausea and hiccups. The last 2 weeks or so I've been excessively tired, and moody. I've also taken 2 pregnancy tests, one of them a week after my first missed period and the other one about a week before my 2nd missed period. Both came out negative. I haven't had any breast tenderness, heightened senses, over-eating. I'm hungrier some days than others, but I haven't gained any weight that's abnormal. I'm 24 years old and my weight fluctuates between 126 and 130 so I've stayed right in there. I'm going crazy. I've been pregnant before and knew for sure by week 2 because my boobs hurt if the wind blew too hard, I could smell everything and I wanted to eat anything in my path and I was tired all the time. Other than the lethargy, I don't have those things. So what does anyone think it could be? Obviously, I know I need to go to the doctor, and I am, I just want other opinions so I'm not blind sided when I get there.