I haven't written here for a long time, only answering lately) but aro…

I haven't written here for a long time, only answering lately) but around 30 weeks in the evenings, my belly was getting smaller, not very often, the gynecologist says that it's normal, it's natural for my body to shrink, train, according to ultrasound and tests everything is good, but now something has started that wasn't there before, my belly started shrinking for no longer than 1 minute and with an interval of no more than 2 minutes (the interval and duration are the same for a couple of hours), while I don't feel anything, only frequent urination and barely noticeable dull pain like during menstruation, so I think this could be Braxton Hicks contractions or is it just muscle tension?