Cramps but no period

I have been getting cramps and lower back pain for about two weeks now. 1/4/2015 my husband and I had unprotected sex; since we are trying. The pain is worse at night, I'm a few days into my period week and Nada.. I am dealing with some mild cramps and random fluttering. I am also super HUNGRY and more tired.. The day after we had sex I've been super exhausted ever since. But I'm always kind of tired. We are hoping that we are pregnant. I've been researching like mad.. I just have no idea, except for waiting. Thoughts?