Is it normal 4 a pregnant dog to produce milk after giving birth?

Yes - sometimes female dogs can have a phantom pregnancy where their body acts as if it is pregnant when in reality it is not. This can result in milk production and usually the dog's belly will swell, she may begin acting differently too. She may show nesting behaviour where she tries to find a suitable place to have her 'puppies'

She also may begin to treat her toys as though they are puppies.

If your dog is showing these signs I recommend taking her to a vet to check that she definitely is not pregnant and to get advice about how to deal with phantom pregnancies.