Cervix behind baby's head?

Kelly
Hi All, went for my 38 week appointment yesterday and my Dr was unable to determine if I was dilated yet or not because my cervix slipped behind the baby's head (baby is sitting very low). Has this happened to anyone before? Dr didn't seem concerned in the least but it was a very painful examination because of this and I'm just hoping it will move back to the front soon! Thanks in advance for any feedback!