TMI but has this happened to anyone with a C-section?

Hey ladies....ok I know this may be TMI for some but I have never had this happen to me before and can use your suggestions!
I am 6 months post my beautiful healthy baby girl. I was induced at 41 week but had to have an emergency c section.
About 2 weeks into my recovery my incision reopened. They re bandaged and restricted me to heavy lifting, driving, sex, ect for another 8 weeks. They also put me on an antibiotic in case of infection.
Well two days ago I had some swelling around the scar and it felt sore to the touch. At first I thought it was bc me and my husband had sex recently. But then last night I felt what feels like a small hard ball right in the middle of the scar. 
Then it filled with fluid. My husband thinks it's an in grown hair. I've never had an ingrown hair so I'm not sure what it is.
Then This AM it popped and is leaking fluid. Not blood, just milky clear fluid (puss)
Has anyone had an ingrown hair right on your scar? Does it sound like that's what this is? Or should I call OB just incase?