Is this "normal" ? I'm 20 days post op, tummy tuck surgery and I'm so worry about this spot. (photos)

At 20 days after surgery this is not the start of an infection.  Small areas on the wound such as this are not a problem after surgery and do occur commonly.  The plastic surgeon needs to be involved in the care of these areas.  I would not wait 2 weeks.

This does not look like an infection. Many patients have small areas of separation along the incision with more swelling above than below, so this is not an uncommon thing to see after tummy tuck. Continue to follow up with your surgeon as scheduled and watch for changes. Call the office if you have drainage, increased redness, new or different pain, or other concerning symptoms.  Otherwise, this should heal just fine.

It is common to see some difficulty with wound healing following a tummy tuck. The skin edges are under a lot of tension and sometimes they do not heal together properly. Close followup with your surgeon is recommended. Infection is much less common and is denoted by redness, drainage, pain, and fevers.

You are having a minor wound healing issue Which can happen quite often. Thought most patients end up having good healing and s good scar, Meet your surgeon he'll help you sort it out faster

Appears as a wound healing issue. Best to see your surgeon sooner(like today, Dr LaGrasso is on goggle so you could find which clinic he is ad today) or seek in person second opinions from the over 80+ boarded PSs in South Florida like me.  

if not red or hot or draining, relax, clean it every day, let it air dry until scab falls off, it will scar fine,please contact your plastic surgeon with any issues.

There can be separation of the edges of skin along the incision and it is not uncommon for this to happen after a tummy tuck.  You should return to see your PS so that the wound can be assessed and some local wound care done to help with the healing process.