Hard belly?

Cassandra
I'm 22 weeks with twins and for pretty much all of today I've felt like my belly is just really hard, heavy, and sore. I don't think it's Braxton hicks because it's not waves, it feels constant. Babies have been active and I found both heartbeats easily with my Doppler. It's just getting exhausting and uncomfortable. Has anyone else felt this way, did it ease up?