
I have to agree with other comments, your breed is not the breed for the first time breeder, if you do get her pregnant are you available 24/7 to rear/supervise the pups as this breed is well known for being poor dams, they either will not have anything to do with the pups or may feed them under supervision but not stimulate to toilet so you will need to be there to feed and toilet every 2hrs through day and night.
Puppies need to be kept very warm[ weather getting cooler by time pups are due] if they get chilled for even a short period the canine herpes virus to get hold and pups will fade and die.
When you bought your dogs did you let the breeder know your intention to breed so you got pups that were potentially show/breed quality rather than a pet quality pup?
You may think your pugs are beautiful but have you had them assessed by a show judge or independent breeder that they are both breed quality?
Are they compatible re pedigrees, this can be checked on the KC website.
In view of your male struggling to breathe when physically exerted I would abandon any plans to breed with him, you would not want him passing on this problem to his offspring nor would puppy buyers be happy to buy pups that may need lots of vet care throughout their lives or be returned to you for refund.
Our comments may be upsetting but you asked for advice and it has been given, you can go to other sites and be encouraged to continue but here you get the truth from members who have either had problems with your breed or have read posts of the outcome of breeding from this and other breeds [there is a thread on here at present]and desperate for help and advice so please take the comments as they are meant.