Reverse dilation?

One week ago I was at my OB appointment when he checked my cervix and stated I was dilated 2-3 cm. Two days later I went to L&D with lots of pressure and they checked my cervix and I was up to 4cm.

Today (7days since last appointment and 5 days since L&D visit) I have apparently shrunk to 1cm?? Is this even possible?

My doctor seemed very off, he is going on a two week vacation and wants me to hold off until he is back.. which yes I would love to have my OB deliver but this seems fishy and I’m feeling uncomfortable with the way this is being handled. When I asked how do I go from a 4 to a 1 he had no answer for me and had his student check baby’s heartbeat and he left the room and never returned.

Should I be looking for a second opinion? I have been having terrible pain in pelvic area and lower back pain which I believe to be contractions.