I'm 2 weeks post tummy tuck, is my belly button closing or is it just misshaped? (Photos)

It appears from you photograph that the redness is probably secondary to normal wound healing. However, there is an area that looks suspicious at the bottom of the incision that may be related to a spitting suture. I have found that belly buttons, while they may be narrow in the early postoperative phase, tend to widen a bit as time progresses. I would recommend you go back to your operating plastic surgeon for a wound check. Congratulations on your surgery

I do not think your belly button is infected.  This kind of redness is common during the early weeks post-op.  It is indeed narrower than normal now, but should widen as the welling subsides.  If it does not take on the shape you desire, you can (and should) discuss a revision with your surgeon.  Good luck.