Signs of pregnancy

Question
My labs first breeding date was Sept 20 and she breed for 15 days after that. She could be anywhere from 4 to 6 weeks
along. Her nipples are getting larger and she is alot bigger in the middle. She is eating us out of house and home and then some days she will eat the cats food and treats and not her food. Everything I have read says a vet can not tell only by ultrasound and xrays. Everyone says let nature take its course but I Have mixed feelings. Any thing else to look for before the vet. Plus we do have homes for the puppies/

Answer
Hello Glenda and thank you for questions

She sounds like a typical pregnant dog, the pregnany weigh gathers in the section just below the rib caqage or in genral the dogs sparsely haired belly area which will take away a fit dogs natural curved aperance, Since her nipples are enlarger and you can tell shes getting wider I'll say more like 5 to 6 weeks.