ugh bfn!!

So today is 14dpo, af is due today and I decided to take a test w fmu and bfn. it's really disappointing bc I have so many pregnancy symptoms and just feel pregnant. this would be baby #3 so I know what to feel for...or so I thought. I know every pregnancy is different but I was just so hopeful to see that second line. maybe I'm just one of those women who takes a while for hcg to build up or maybe af will show her ugly face today and I was imagining everything. ugh! thanks for letting me vent! anyone on here ever get bfn (I'm talking like stark white!) on 14dpo and then get a late positive?