Is it normal to have a bump on incision 3 weeks after abdominal surgery? (photo)

You do not have pain, you do not have any drainage. You have an inflamed reaction and likely once fully healed this will be a lumpy scar. I do not think this needs immediate attention. I would allow it to fully heal before revising the scar to give you a nice result. You will not be harmed by waiting a few days to see your doctor.

You may have fluid or pus collection under the area. Have your surgeon examine it. This may happen as part of healing and will heal fine once taken care of.

The area you are referring to is a young scar. It will remodel for up to one year so just give it time. If after a year it has not settled you could have a scar revision, but it is too early for that at this point in time.

it is very important to rule out incisional hernia ,the second possibility is an abscess,An USG will be helpful

Appears as a suture abscess, seek immediate drainage by opening the incision. Best to be seen very soon to prevent an infection.//