I have a Yorkie poo. She's about 10lbs. I bred her with a proven Yorkie stud 54 days ago. He is about 5lbs. Her nipples are enlarged and she has been showing mothering instincts. He only problem is she's not getting a pregnant belly

this is her second litter so I thought she would get fat like last time. I have an appointment for her tomorrow at the vet but I don't want to pay extra for an x ray if she's not pregnant. I'm super worried