AF a week late & still BFN, has this happened to anyone else?

Ca
AF was due to show June 29th but never did. I just took another test and it was negative. Is it possible to be pregnant but it's just taking a long time to show on a test? How long should I wait before being concerned? Could I even be pregnant still or am I just getting my hopes up? I'm never usually this late. I'm usually within a day or so range. Thank you in advance for any advice!! ❤️