What is this little bubble over my incision? (Photo)

Hello, there are several things that can cause a small lump along your incision so you will need an assessment by your doctor.  A common cause would be a small stitch coming to the surface, but other causes include an incisional cyst, benign lesion called a granuloma,  small localized abscess, or other issue.

In that area, it is most likely a stitch irritating your skin.  Make an appointment to see your surgeon if it is not resolving.  

Most likely it is a suture deep down that has not dissolved
yet and so the body is trying to reject it and you get a small swelling that
you describe that may even open up and some fluid will come out. Often times
that is followed by feeling a small suture knot beneath the skin. Have your
surgeon take a look.

Although this looks like a minor issue, it is one that needs to be addressed by your surgeon.  It is likely an inflamed suture, and a small opening to remove it will probably be advised. All the bset.