What Causes Less Bleeding Than Normal And Stomach Rumbling?

I'm wondering if I could be pregnant. I used to have really bad cramps and heavy bleeding but the last few months my bleeding is normal and cramps are almost non existant. In addition to that my stomach grumbles really loud and it almost like I can feel it usually when I'm at work between 10am and 11am. I have taken 2 hpt both negative and I have not missed a period. Any idea what is causing this?