Transcervical Insemination

Question
Hi- i recently did a transcervical AI using frozen semen, on day 28 an ultrasound was done by a general vet, he didn't see any pups however, the bitch continues to look as though she is pregnant enlarged teats etc- is it possible that if a there are only a few pups and the location of the pups or pup we could have assumed she wasn't pregnant?
He the US with her standing , no shaving of the hair - we did stage her with progesterone screening-
Should I have had her ultrasounded by a radiologist who is experienced in ultrasounding instead?
This golden retriever bitch is 4.5 years old , normal cycles, 1st time bred-
Many thanks for your time
( bred 2/27 ultrasounded on 3/26  as of today she is day 34 post breeding

Answer
Hi Laurel

I prefer x-rays done after day 50 for clearer results.  You have to wait until that long as the bones don't calcify and nothing will show.  X-rays are completely safe to the pups and the dam. Pups can "hide" in larger breeds like the Retriever and may not be apparent until later.

Good luck