I'm seven days late......still no BFP

Katie
This is our first month TTC. I stopped taking birth control, and had af. I tested with ovulation sticks and I definitely ovulated (pains and all!) I took a pregnancy test a day after my expected period and BFN. I have had no period symptoms all I have is some nausea that comes and goes throughout the day, sensitive nipples, and maybe a little more tired? It's hard to tell with tired, I work nights and in school full time. I'm now seven days late, still no af OR bfp....help I'm going crazy!!