female pom yelps and runs at penetration

Question
im breeding my 2 year old 5lbs female Pomeranian to a 4 year old 4lbs male Pomeranian that has produced two other litters. this is my females first time breeding and today makes it day 14 of her cycle. she is standing for the male to mount her and allowing him to trust but as soon as he makes contact and penetrates her she yelps rolls over and runs away. what should i do to help with the mating? when i take them out to help assist they show no interest in each other when were in the picture.

Answer
She may have a stricture inside of her vagina. A quick trip to the vet would tell you for sure. Some females are just really scared their first time. I would have an exam done just to make sure that everything's fine inside of her. If it is, then you may have to consider sedating her.