going crazy

Claudia • Newlywed, wedding photographer, Christ follower.
I feel like this is the only place I feel safe sharing this...
I haven't been on any birth control for almost 3 years, and although I wouldn't say we have been TTC (I mean, what exactly is that by definition?) I have always been open and hopeful for a pregnancy. 
My period is 3 days late and I tested negative for pregnancy. But the thought is driving me crazy. When this happens, I obsess about being pregnant. I feel like everyone around me is pregnant and that I'm the only loser that can't achieve it. Please don't take offense, I do not mean anyone is a loser. I even went so far as so look up healthy foods to eat while pregnant and went and bought them in case I AM pregnant.
What is wrong with me? Is it cause I'm in child bearing age (I'm 30)? This is really hard :(