Mixed advice on movements

Hey ladies, FTM seeking reassurance. From 18 weeks bub has been a prolific kicker. I have videos of him kicking up a storm that can be seen from the outside at 23 weeks and he's normally super active when I'm about to go to bed. 2 days ago he went a bit quiet, still felt movements but no distinct kicks or particularly active periods. Yesterday I saw my OB and mentioned this, she monitored baby's heart rate for 40mins and wasn't happy with how little baby moving..apparently his heart rate didn't have as many accelerations/decelerations as they would like to see. OB referred me to another OB who did an ultrasound and told me bub was fine, blood flow through cord and brain was good, saw swallowing and practice breathing but couldn't get him to move anymore than a squirm. This OB told me he didn't give much weight to decreased fetal movements.

My OB called me after and told me if I'm concerned about movements come straight in.

Today I've felt bub wiggling or squirming but no kicks and nothing hard or strong. I don't know whether to be worried or not....I'm 31 weeks so figure he should have room to move still