Pressure in lower abdomen! Help!

I’ve noticed for a few months that when I would lay flat on my back that a golf ball size knot thing would come up in my lower abdomen. It isn’t painful it just sticks out when I lay down and makes my skin feel tight. Well as a few months has passed it has gotten bigger and is messing the my belly button nerves. It scared me because it literally felt like it did when I was pregnant with my baby and he would kick me in the belly button. Anyways fast forward to tonight it’s gotten much bigger. The pressure goes completely across my lower abdomen. It doesn’t hurt it’s just pressure and something just feels off. It just doesn’t feel normal.

I’ve been having my periods regularly. They’ve been lighter then normal but I’m having them.

Any ideas what it could be. I’m starting to kinda get worried.