[Acne] Why are my pimples leaving a red mark when I didn't pop them or mess with them?

Beauty Tips For Body Care
I had three dime sized pimples on my cheeks. I didn't touch them, pop, or pick at them. I left the be. I did tho add a little bit of 10% benzoyl peroxide, making the white head go away. But, after 2 weeks of having the ex-pimple. it has left a red mark, i'm not sure if its a scar or what not. I'd just really like to know.
Girls Blog 2015
Submitted by Internal_Rich