Why does my four year old c section scar look like this?

The muscles sort of bulge a bit over the top even though I’m in good shape. And it’s crooked. I assume the crooked part was just from the way baby was laying when they cut? But still, you’d think they’d be able to give me a straight line there 🙄 But what about the bulge?

I was checked for diastasis recti after giving birth if that matters (and didn’t have it). 

Pardon the imprint from the elastic of my pants.