What should be expected with pomeranian-chug puppies?

Approximately 4 or 5 weeks ago, my family inherited a female tan chug and a male chocolate Pomeranian, both fully grown. Last week we noticed that the Chug was looking a bit rounder and that she was acting really strangely when people would try to pick her up (contrary to before, when all she wanted to do was be held). We took her to the vet because we read online that pugs, let alone chugs, have a hard time giving birth and can have many complications. All he really told us was that she was definitely pregnant and that it may be possible for her to give birth to the pups naturally. I've searched online for any information on Pom-Chug mixes but nothing has really turned up. What should we be expecting with these puppies?