Confusing dates..

I discovered June 19 I had a missed miscarriage. Bled from the 19-26. Had a chemical pregnancy then had my next period July 19-26. BD July 28,29, and 31. Pretty sure i got a vvvvfl on a test last night. Tried dating the possible pregnancy based on the first day of my last period (7/19) and said I would only be 2 weeks and 5 days (which seems way too early to be getting a positive test.) but based on if I conceived the first day we BD, 7/28, I would be 3 weeks and 3 days. Is it possible to had gotten a faint positive last night? What date would I go off of? Included a pic of the test and pics of predicted fertile week. I thought they had predicted my fertile week a little early... but maybe not?