As you know, a tubal ligation is one of several procedures by which the fallopian tubes are either cut, clipped, or blocked from within. Your periods are regulated by interactions between hormones of your pituitary gland (brain), ovaries, and uterus. The fallopian tubes don't play any role in this process. Also, the tubal ligation doesn't prevent ovulation, meaning that your cycles should continue as they normally did before your operation. If your periods are markedly different now, it is probably due to a different reason other than the ligation. It must be a coincidence that this change in your cycle occurred around the same time as your procedure. Characteristics of your cycle including length can be effected by age. So depending on how old you are, this might be a reason. There are countless other possibilities that could explain you being late that should be considered. My advise is for you to schedule an appointment with the physician you see for your feminine health (either primary care physician
or OBGYN). He or she will be able to take a more thorough history and physical exam which may help you get to the bottom of why your cycles are changed. Perhaps it is something reversible that your doctor
can address. Good luck.