BFN but on missed cycle day 6

Hey y’all I have a question, have anyone of y’all ever gotten BFN’s for the first week of a missed period and then down the line got a BFP? I’m so confused because my period has been mostly consistent 28 day cycles for a while now and I keep feeling “sick” breasts hurt, cramping but no period. Then I’ll go test and get a BFN. I’m wondering if I’m testing to early for my body to show (if indeed) positive. I’m confused y’all either I’m just not pregnant and my period is stalled for some reason or possibly preggers. 🤷🏻‍♀️Thanks for reading