She should be having some discharge. Red is not concerning. If the puppies are gaining weight, then she is ok. Are you weighing them twice a day. It is a HUGE job, so give her what she WANTs to eat. She probably ate a lot of placentas while in labor and a lot of bitches are not very hungry for the first day. Not concerning if she is drinking. Check to see if she has a temperature. If her temperature is at 103 or over, that IS concerning. The box can be too warm, or she can have a retained puppy or placenta. Normal temperature is around 101.5 - 102.5, so 103 is a slight temperature.
The more information you have when you call the vet, the better off you will be. And, if at all possible choose a clinic that has a reproductive health department, because ordinary vets do not see enough bitches in whelp anymore, and they do not have the best information to give you.
From what you wrote, I would NOT call my vet unless the further information of temperature and puppies condition warranted it.
Also, puppies DO lose weight or do not gain, generally for the first 24, then they should be in the neighborhood of a 16-20 ounces and they should be gaining about 2 ounces once to twice a day. If after the first 24 hours, they continue to lose weight, then they are in trouble. If some are gaining, and others are standing still, give it another 12 hours, and kind of move the once that seem to be empty up near the rear teats.
Heidi Ho, Odie
Joy-Joy, Bear Cub, Hepsi-Pepsi
Cujo2, Karma Chameleon
Ramona the Pest, Kojak -- who loves you baby?
Tiny Tinnie, Susie's Uzzi, Kaiah -- The Baby Monster.