Bernado is teasing your typos... Assuming you really meant "dog", "pregnant", and were only talking about females: if allowed to, I think a bitch can have pups every year more or less as long as she lives.
However if you let this happen she won't be happy or healthy and won't live so long. You'll also have to find homes for dozens and dozens of puppies.
A bitch should only be allowed to get in pup once or twice in her life at most, and then only if you are certain you can find really good homes for all the pups, and that she carries no genetic problems. Then spay her. If you are not sure, it's best to spay her straight off anyway to be on the safe side -- you may not want pups, but she will have other ideas!