Hi there. Thank you for posting a question on Ehealthforum. Tubal ligation (TL) does not normally effect your periods and the fact that they are now coming every 14 days may not be related to your TL at all.
Pain following intercourse is however a different matter and might reflect a small complication related to your TL. I can not make a diagnosis of course and it is very important that you ask your GP to refer you back to the unit where your TL was carried out. While there probably is nothing too serious amiss it is however imperative that you get yourself sorted out asap. Good luck.