Just turned forty spotting during ovalation and i have tubal ligation done in 1999 is this normal?

Ovulation spotting: As a woman ages, the ovaries require more stimulation from the pituitary to produce an egg at ovulation. This provides a large increase in estrogen production, and that level of estrogen drops to near zero just prior to ovulation. Similar to why bleeding occurs at your menses, degeneration of some of the lining of the uterus causes spotting to frank brief bleeding: i.e., it is normal.