What’s going on ?????

I’m 14 DPO and AF is 2 days late. I honestly don’t know what to do. I keep taking test and they all come back as BFN. I’ve been having symptoms as if I am pregnant but every time I take a test I have a BFN. Any reasons on why I keep getting BFN??? Ive been trying to conceive for 6 months now. Any advice is well appreciated. Thanks ❤️