I have just found a suitable dog to mate with my little bitch. (Both fox terriers). I am new to all this but my bitches breeder is helping me every step of the way. He says i should mate her up 10 days after she first came into season, and he breeds alot of dogs but someone else told me two weeks. I want to do this right, so does it matter? Thanks

Certainly not usual up to 10 days, bitches are all different and it could be any time between 7 to 24 days. Only way is to do some sort of test and as you have no experance I would suggest you have a blood test done by the vet starting from the time the discharge changes from blood colour to staw colour, that is always assuming that your bitch does change colour, most do.

When do i need to have these blood tests done and will my normal vet be able to carry these out?

I usually do the test on the 10th day, if your lucky you will get away with one test. Yes your normal vet should be able to do it but it will have to go off to a Lab. I am lucky my vets is a hospital with their own Lab so I get the result within 2hrs. I should give them a ring asap and ask. Good luck.

Bitches vary when they are fertile during their season. Every bitch is different, and every season is different in each bitch. I successfully mated one of mine on day 13; for her second litter she wasn't ready till day 18. So be guided by her.

11th and 13th day is what used to be said years ago, but every bitch is different.  My Spanish are nearly always mated on their 18th day, although I've known others to be mated on the 9th.  It's not so  bad if you don't live too far away from the stud dog.