Cramping, BFN, & no AF

I Don't have a primary Dr., and there are really no female Dr.'s out here where I live. I'm not totally against male Dr., but it's just more awkward. 
Anyway... I haven't had a period since Aug. 26 and I've been taking lots of tests. All negative. For the last 4 or 5 days I've been cramping like I'm going to start, but nothing. It hasn't been too bad except the other night I went to the bathroom and couldn't go back to sleep for about an hour because the cramps hurt pretty bad. My husband and I have been trying since May, and I'm really scared.