Tightening in belly… 19 weeks

So I’ve been feeling like tightness at the top of my belly, it almost feels like baby is balling up at the top. And it’s happening to me a lot and I’m getting concerned it might be early contractions? Idk if it’s possible for baby to ball up at the very top of my uterus. They don’t hurt, it’s more uncomfortable tightening, sometimes I also feel an aching in my legs when it happens. Is this normal? I know about Braxton hicks. This feels different though.