What is a false pregnancy?
A false pregnancy is a situation where the female dog exhibits symptoms of pregnancy even though she is not. The symptoms occur at the same time after her season as when she would have been pregnant had she been bred.
Some of the symptoms are swelling of breasts and possibly milk, acting more subdued, possibly even having cramps around her "whelping date". She may even start carrying around or nesting with toys (her babies).
Most female dogs seem to go through false pregnancies to varying degrees. In fact, I would worry if one didn't have her breasts swell up a little after her first heat. It's just that some get more enthusiastic about it than others.
There will not be any vaginal discharges with a false pregnancy, so if there are any it is wise to take her to your vet to be sure there is no infection. There is no need for treatment of false pregnancy. It will eventually go away when her "whelping date" passes.
(Chris Levy, Abiqua Miniature Schnauzers)