Irritable uterus


I’m 24 weeks pregnant and I posted a few days ago about continual/frequent Braxton Hicks and since then I’ve noticed it more. They do get better when laying on left side and drinking water and they aren’t painful, Just causes tightening. Last night I had about 8 Braxton Hicks in one hour but fell asleep.. woke up this morning and was fine. I was on my feet some this morning going to the grocery store and cooking... Then I started to get them again after eating lunch. I’ve probably had 10 in the last hour. During that hour I was sitting upright at my computer and drinking water like crazy.. I decided to call my midwife and she didn’t seem concerned. She said as long as it wasn’t painful it was okay (and as long as I didn’t have bleeding, back pain etc) but she said it sounds like I have an “Irritable uterus”... what is that? Anyone have this same issue?? now I’m resting on my left side and they’ve gotten way less. I’m just so paranoid because I was underweight before I got pregnant and was told I have a moderate risk of preterm labor.. Is this common?