
Are bitches usually mated quite early on in your breed or more like around day 15 as with mine.
With the latter I would get a baseline done 8 - 10 days from when you found the first blood, unless she obviously starts a season from scratch before then.
My last bitch to have a false start like this I sent to the breeder of the stud (stud dog belongs to my lovely friend, their daughter) two weeks after she started, he told them clearly she was not ready/in season, and she came in properly two weeks after arriving there, and stayed there until after she was mated (two weeks after the second show), which meant they had her for a month.
It means she absolutely adores them, and they have handled her to a RC and a CC for me when I needed a handler in the challenge.