Lump under stretch mark

I gained a ton of weight this pregnancy and ended up with a bunch of stretch marks. I’m ashamed to say I’m 225lbs now which is the highest I’ve ever been. I have a ton of big stretch marks on my stomach and I was putting cream on them and noticed that I have a little soft lump under the biggest one. It’s shaped and feels like a small grape (maybe half the size of a grape). It’s kind of squishy and rubbery and moves under the skin. What the heck is this?