Do NOT pull it yourself. The best thing you can do is not touch it at all, except maybe to clean it, put some antibiotic ointment and a bandaid on. It sounds like you have a little infection around the stitch, which is probably ok but might need antibiotics, so call the doc and let them know what it looks like. People do "spit" stitches sometimes, and sometimes they leave a knot poking out, so don't worry too much. The pain, swelling, and redness are more of a concern.