Do women ovulate during their menstrual cycle? what is the % of women who had tubal ligation 5+ years ago chances of having a full term pregnancy?

Menstrual ovulation?: Ovulation almost never occurs at menstruation. Many women mistake Implantation bleeding or bleeding from other causes for a "period" at times. Failure rates of tubal ligation depend upon how the tubes were interrupted via cautery, clips or ligation/excision with separation. Those rates vary between 1/500 to 1/10,000 with ligation/excision and separation being the most effective @ PG prevention.