Maybe you were just testing too late for OPK? I've never tried so I don't know, but maybe you ovulated earlier than you thought? Maybe it is the stress doing it? How much schooling do you have left?
I'm kind of symptomless today. Normal backache, I've got a bit of a headache, my carrots taste off... last night I started crying at the grocery store when I realized all I wanted for lunch this week was kid snacks (snack-sized applesauce, tapioca pudding, cheese and crackers etc.), and I never cry. Ever. Hubby thought it was funny. My stomach was super upset last night, I was walking up and down the aisles going "nope, nope, nope, nope" at all of the regular lunch-foods, and then finally when I saw the snacks I wanted them. And four boxes of Frosted Cheerios. And then we found a banana pie mix and I got all excited, but when I read it, (it said all I had to do was add bananas, milk and butter) I got super angry because who would want to buy a banana pie mix if you have to provide three of the most key ingredients. Hubby just laughed again.
If I'm not pregnant then I don't know what is going on with me. I've never been like this before.