I am 44, have always had regular menstrual cycle - exactly 28 days - i had my tubes tied after my twins 13 years ago. for the first time ever i am two weeks late? i have also gained a lot of weight over the last few weeks. please advise?

Late for period: At age 44, the ovary requires much more stimulation from the pituitary for ovulation to take place, which of course delays the onset of a period. This is very common in late 30's to age 50 or more, and after producing more pituitary stimulation, you may continue to have periods on a regular basis for a while, and then a similar gap may occur before the next.

Peri menopausal age: You are at the age range for peri menopausal symptoms to begin with irregular periods and possibly hot flashes. First run a pregnancy test as tubal ligations can and do fail. If negative, a GYN MD appointment to discuss the "change of life" issues may be warranted.