It isn't fair

Sophie • I`m a teacher. My husband is a pharmacist. We have not used bc in 3 years...
I am five days late from my average cycle length, one day late from my longest. I have had four negative pee tests and one negative blood test. I still haven't started. Has anyone had a negative blood test and still ended up pregnant? I feel like I have been trying for ever. I'm totally depressed now, don't feel like doing anything. 
I guess I want to know that I'm not alone. Please comment.