Hello I wonder if anyone could help.
I've got a lhasa apso Maiden bitch who started her season on the 14th of nov(that a when I saw the blood). We contacted the experienced stud and took her for first mating on the 25th. She wasn't happy and very snappy but eventually she allowed him to mount few times. There was only slip matings  despite them being together for a long while. We tired again the next day and she was very responsive and in his face. Stud mounted couple of times but once again just slip mate and then he completely lost his interest. She isn't swollen much at all and her blood loss is very small from first mating  but she keeps herself very clean. Have we done it too late or too early.?

Without progesterone testing, you can't really know.  There is absolutely no sign.  Otherwise everyone would be using that instead of schlepping their girls to the vets for blood draws.

You can either wait and see if it worked, or if the stud owner is willing, keep returning every couple days until she really loses interest and stops allowing him to mount.