24 day cycle. When to test??

Madalyn
Does anyone have or have had around 24 day cycles? And if you did/do have you gotten a BFP when AF was late? Or did you have to wait and test till cycle day 28 to get your BFP? No signs of AF but i got BFN this morning 😞 my 24 days started at my last miscarriage october last year.