
What you choose to do is up to you all I can tell you is my experience recently.
I will cut an incredibly long & farcical story short. Had a progesterone test, was told to get her to the stud right away (fortunately I was using my own boy so there wasn't the incredibly long journey to a stud dog). My boy wasn't paying a blind bit of notice nor was another dog that I drafted in from a very kind lady just in case my young dog was a bit clueless. The next day I had a smear done & was told that she was nowhere near ready.
One week later, my boy tied with my girl. Because she had missed on a prior mating I went to get a smear done out of fear that we'd got it wrong (this was 3 days later) & I was told that she was right at the end of her "fertile window". Boy had mated girl again between times.
I know some people do not like cell cytology, but I think (as always) if you get someone who really knows their stuff then it can be an invaluable guide.
Can't tell you if it's a happy ending for me yet, but I wish you a lot of luck. Keep us posted.