Pregnant or stomach bug?

My husband and I have recently decided to try and have a baby, this is our first month trying during my fertile week. My period isn't due to come until 8/12 so I know it's too early to take a test, but for about 5 days my stomach has been feeling "off." It's been upset, slight cramping, gas, and it keeps turning like I'm hungry but when I eat I can only eat about half (if that) before I feel really full and then it starts to ache again. Has anybody had something along these lines in the very early stage of pregnancy? Or maybe it's just a stomach bug?