things have not gone to plan even after extreme planning and numerous Idexx tests we only managed acouple of 5-10 second slip matings on Sunday evening, the stud owner thought my girl had gone over which I wasn't convinced about.
However she is a coated breed and while I was trying to sort her out this morning ie clean out bits of tangly blood etc from her season before full bath at weekend, noticed she was flagging her tail! she would be approx 26 days with an Idexx count of 17.6 on day 20, I just need anyones experience with a girl that has still flagged when she has gone over or is there still a chance for a mating even now?
thankyou.

I would definitely say with that count she hadn't gone over even now and I'd be taking her again to be mated.  Did you not take her back after Sunday?

no because when the lady from lab phoned on Friday she said 24- 48 hours from test (thursday), so I took her Friday and the boy wasn't interested, so I took her again Sunday and he still was very half hearted although she was very keen nothing happened. I was very lucky in that I got a chance with my second choice stud, even though now this boy was extremely keen but she was having none of it  had stopped flirting and standing and we only managed a small bit of action before giving up, the stud owner said she may have gone over (although she had been standing a few hours previously for the 1st dog) and because the Idexx lab had said 24-48 hours which we had now passed I agreed that maybe she was right.

The 24 - 48 hours would have been when the eggs first became fertilizeable, (unless they meant ovulation was likely in 24 - 48 hours which would give you two more days) they then will be viable for about 2 - 4 days.

Some studs like their bitches very ripe (3 days after ovulation, so in your case Sunday if she ovulated Thursday), and some bitches will only stand for a day.

thanks ladies for your thoughts, I have not taken her again as the flagging stopped, but thankyou for the invaluable advice which will come in very useful if I try again - in which case I will start testing later in her season. To be honest it was the weekend that threw me, as I couldn't get the results back and panicked that we would miss our chance. I still have the tiniest hope with the slip mating, (which we know  would have worked if one of the farm dogs from down the road got in the garden!)
xx