We just brought home our new sheltie puppy saturday and last night I noticed a swelling protruding from the belly button area. It's a little larger than a pea sizE and pink and is soft and disappears when you push on it. It wasn't there on saturday . He has an appointment in 3 weeks and is 6 weeks old. Anyone had experience with this? Should I be concerned now and get him in to see the vet sooner, He's rompin around and eating and drinking just fine.