Mini Pin in heat

Our mini pin started to bleed on Sat. so my wife called up a lady that had a male, that she wanted to breed with our girl. My quesyion is, how far into the cycle is the best time for her to get pregnant? She is 4 yrs old and other times when she was in heat her stuff seemed more swelled or puffed up than it does right now. I think its too early my wife says no. any help would be greatly appreciated.

[have 2 kids]

Dogs will mate towards the end of her cycle.   I know larger dogs have a cycle of about 3 wks.  I'm not sure with smaller dogs.    If she isn't ready to mate she will let the male know.      

[ginger899]

All dogs have a cycle of approximately 3 weeks. They are not ready to mate until about 4-7 days right in the middle of the 3 week cycle. So that's the middle week. When she shows signs of her vulva reddening and swelling that is when she is most ready.
That's true -she will definitely show the male if she is not ready. She will snap at him if he tries anything. If she does that, don't scold her. Doing that is natural, won't do him any harm. When she snaps at him, he will usually back off and wait.