If you had a tubal ligation, you are basically sterile and only one in a million women
would have some kind of complication and become pregnant
So, I'm guessing you aren't pregnant.
But periods can still be late as they are related to our hormones and our hormones can fluctuate. Have you been sick lately, stressed, changed routines. lost or gained weight, possibly have a slowing thyroid, etc? There are many reasons why hormones can make us late and most are not a big deal.