During the early stages after conception it is nearly impossible to detect whether a female dog is pregnant. This gets even more complicated for obese dogs. However twenty to thirty days since conception, it is possible to feel the abdomen and if there are uterine swellings around the placental sites that feel like firm and discrete lumps, then most likely it is a pregnancy.
How Do You Tell If Your Dog Is Pregnant Without Taking Her To The Vet? She's Not Getting Very Big But Has Other Symptoms.
Your dog's nipples will begin to get pinker and larger and she should start to gain weight