Infection - cause for concern?

The picture attached was, taken this evening, March 18th. I have to admit that I"m pretty worried. I ended up seeing the doctor again today during my lunch hour. (Note: about 10 minutes prior to lunch I went to the bathroom and noticed bright red blood on my far right hip. I put a piece of paper towel on it, but after getting up off the toilet, there was even more blood. I called the doctor and then zipped over to his office (5 min away) and he looked and said that a stitch from below the skin made its way up to the top - he said there's a lot of stitches that he used, and this wasn't abnormal, and that I could take the gauze off tomorrow morning with my shower. That's the reasoning for the gauze on my right side. I'm not worried about that)(right now)   That said, the redness in the centre is giving me cause for concern. I was prescribed yesterday apo-cephalex 500mg, and I'm taking 1 tablet 4 times a day (every six hours). The redness tonight is warm, and hard. It hurts to sit because I'm bend at that point. I've only been on the antibiotics for 1.5 days, probably not enough time for them to work. I'd appreciate opinions on whether this will go down and get better with the antibiotics I'm on. Thanks.