Its fairly simple to get a long swab and a slide with some dye and check your bitch yourself. I know this is off topic and you asked a specific person a specific question but since id like to share here i go LOL...

Sorry about the bad pics... i think youll get the point though. These were taken from a bitch we had we were doing ai on. We took a swab from her canal to analyze her cells. When they become cornified(like they got corners on them) is when her eggs begin to drop. She will be fertile after that for a few days (ive read 3-10 days).
Here is a diagram u can follow...

http://loudoun.nvcc.edu/vetonline/ve...aginalcyto.jpg


This is her on day 1.... notice no cornified cells


This is what the cells should look like when she begins to drop eggs... this was day 7. Although the bitches prime days seemed the be around 10. You can see the cells are cornified