Breeding /split season

Can someone please tell me. I am trying to bred my dog and I think she has had a split season. Progesterone levels remain very low. Cytology indicating that she was ready to breed immediately. Met with stud and she tied with him yesterday and today. She is a first timer as am I. Her tail is flagging and she is definately interested in him. Would she have tied with him if she wasn’t ready/ovulated etc. But then the science tells me otherwise. Please can anyone help.

Hello!  My understanding is that when dogs tie, the chances of puppies are thought to be increased.  However, I think that this is because it optimizes sperm transfer.  In general dogs are very efficient and will tend to mate only when there is a fair chance of the eggs becoming fertilized.