The answer is : DON'T!!
Unless you plan to become a "professional" breeder then DON'T.
The worry, scares, expense, family traumas, anxiety are not worth it.
A bitch does not NEED a litter to be fulfilled in life. Her health will be better for being spayed. Just don't let her get fat.
Pregnancy, any pregnancy, is potentially dangerous.
I could tell you our tale. It's not a horror story although it's not over yet. . .
Really, I wish I'd listened to the advice I was given. Breeding is for the dedicated. Loving your bitch is just not enough.
SORRY.