Hi,I would be concerned. Any redness, especially accompanied by soreness, swelling or discharge, shows that 'something' isn't right - possibly an infection.
I would suggest you go back to your doctor (Ob, or your GP - someone you trust) for advice.
I had a similar problem, and it turned out to be an excess of suture material (about an inch long that hadn't been trimmed, just under my skin sutures) that was aggravating the scarline. Once the suture material was discovered, and trimmed, healing progressed perfectly.
Jackie.