Muscle twitching, spasming...??

So this is pregnancy number 4. I have 2 baby's that were delivered full term and healthy, and i also had a loss at 15 weeks 3 days and i delivered him the next day.

I am currently 13 weeks 4 days, and the muscle, up near my diaphram, i believe, has been spasming' or twitching. Honestly, i laughed because it made me think of when i was further a long with the first 2, and the babies would kick high and repeatedly kick to move around. Obviously, i know that is not what this is. Lol. But it was the best comparison in my mind.

I don't remember if i had this with the first 2 (they are 4 and a week shy of 7 right now,so it's been a while), but i know i did not have this for my last. Anyone else having this? I am thinking it is maybe the muscles adjusting and tightening as my organs begin to be pushed up and moved. Just wondering if anyone else has had this?