I am 1 day away from my tummy tuck and had a few pinches of cocaine drug 3 days ago, is this a concern?

This is a huge concern prior to your surgery.   You need to call the surgeon ASAP and tell him/her this.  It is imperative for your safety that you are completely honest about your drug use.   

Yes, this is a big concern.
Cocaine causes
decreased blood supply to the heart, which in turn decreases the amount of
oxygen that can reach your tissues. This could cause serious problems or even death
while you are under general anesthesia during surgery. You should definitely
not go through with this surgery.