Tightening balling up feeling ?

I have been getting this balling up tightening feeling on my right side. It comes and goes no pain it’s just a very weird sensation and my stomach on the one side ( usually the right side ) will get super hard and stay super hard for a few minutes (2-4min) and then go away. Well I mentioned it to my midwife and she said pay attention to it and make sure my whole belly doesn’t feel like that.

I thought this was just my baby as there isn’t any pain, and well my dumbass forgot to ask why . I plan to send her an email 🤦🏼‍♀️ but was curious why she would say that? Are these Braxton Hicks instead of baby balling up?