Does it take time after missed period to get a BFP?

Contessa

I’m at 15dpo and tested yesterday and today and got BFNs. AF was due yesterday and has been coming exactly 14dpo all year. Do I need to just be patient? Or is it maybe late for a different reason?

I would hate if I’m getting my hopes up for nothing... this is the first time it’s been late since I started tracking in Jan/Feb.