Confused!!

Lizzie
My period is a 28 day cycle. This month was very different and lighter than Normal. Also off and on. And had a more pinkish brownish color. ( usually it's as red as blood can get ) I'm also cramping and at night a feel nauseous. I already took 2 tests and both said negative. My husband and I have been trying for about 6 months now. Could I be pregnant?