Weird lump after c-section

Hello!

I had a c section March 5th and ever since then I e had a strange lump about 3 inches under my left rib. No where near any bone or near my incision. It is a little tender when I push on it.

What could this be, it’s freaking me out. 😬

My two week check up is Thursday so I’ll ask then, just wanted to see what it could be!