I've had 2 c-sections my most recent one 4.5 years ago so I'm plenty healed up. Anyway, about a week ago I noticed this reddish bubble thing on my scar, I took a mirror down there to get a better look. It looks almost like a bubble with a purplish vein in it or something. At first I thought ingrown hair but I tried squeezing it and nothing happened. After a few days it started to go away. Well today it's back to being swollen and purplish looking. It's about 1/2 inch big. It only hurts if I mess with it. What is this???