Cramping with a short cervix

Hello! Need some advice so I don’t go completely insane.

2 weeks ago they discovered, during a routine check, my cervix is shortening. I am now 23w.

At my previous appt, one month before that, I was 38 mm and 2 weeks ago it was 26 mm (abdominal ultrasound). My OB put me on 400 mg of progesterone daily and told me to take it easy. I have another appt tomorrow.

I have annoying cramping for the last 3-4 days. They don’t seem like contractions, just period cramps that are very manageable. I had these A LOT during my first trimester and I was told to take no-spa up to 120 mg per day.

I do not have any other symptoms of labour (no lower back pain, no discharge of any kind apart from the progesterone, no bleeding) but I still freak out. These cramps appear more when I drive (I still have to drive my other children to school) or stand suddenly. Also, my belly is increasing rapidly nowadays so I can safely assume that it is round ligament pain.. but is it?!

I can go and get checked at any moment in a public hospital with no charge but it is a traumatic experience that I would rather not have if I can avoid it. My pain moves (on my pelvis right where my bladder is or left, right, depending on the moment and it gets better if I rest and stay in bed.

Does this seem like pain related to the shortening of the cervix or normal cramping? I had a cold C section with my other children so I don’t really know how contractractions feel like, I can only assume, but the pain isn’t rhythmic.

What do you think? Thank you!