14 days late, negative tests

My husband and I have been TTC baby #2 for a little over 2 years now. My period had been a few days late before and I would test, it would be negative and period would show. Never more than 5 days late. I am now officially 14 days late today. I have taken a clear blue digital test, a clear blue non-digital test and 3 of the $1 tests. All a few days apart and all came back negative. So basically I've been testing every few days since AF hasn't shown yet and not even the faintest of a 2nd line. Just curious if this maybe happened to anyone else and then got a positive blood test? Idk just trying to keep my hopes up because other reasons for a missed period that I have read, don't seem that would be my case.