Weird pinching sensation

Sasha
Hey guys. So earlier when I was napping I was laying on my left side and I felt a weird pinching feeling. So I figured it was just the side I was laying on. I switched sides and went back to sleep. Well now, it's about an hour and a half later and I'm feeling the pinching. It's not so bad, it's subtle, but definitely uncomfortable. It's on the left side, lower uterine area. Anyone else experience this? What could it be? I'm familiar with round ligament pain. I'm litterally just sitting on the couch watching tv. It's not happening right now but it was when I started this post. I'm 28 weeks pregnant tomorrow. Lol I think that's all the information.