BFN... Even when you're pregnant?

Heather

Has anyone here ever had a false negative pregnancy test? I have a doctor's appointment next week but my mind is going crazy. My period is 117 days late, which I wouldn't be too concerned about if I wasn't having several pregnancy symptoms. I had a miscarriage and D&C last April but my periods were regular after that until January when they completely stopped again. I just really need someone to tell me I'm not crazy...