AF is late... but still no BFP :(

I’m late by 7 days, but still getting a BFN on my pregnancy test. I just don’t understand what could be going on. I am normally like clock work. The week before AF is supposed to come I will cramp and get really tender breast. I haven’t shown any symptoms of that. I am getting really discouraged since we have been TTC for almost 6 months now and my last two were so easy to conceive.