Dear steffie:You had an 84 day cycle followed by a 10 day cycle, then a 33 day cycle. The most common reason for a menstrual pattern like you have described is not having an ovulation every month. In a normal cycle, estrogen is produced all month. Estrogen is responsible for building up the lining of your uterus so you have something to shed each month.
In a normal cycle, progesterone production increases following ovulation and release of an egg.. Progesterone "stabilizes" the uterine lining in preparation for a possible implantation of a new pregnancy. If you are not pregnant that month the levels of estrogen and progesterone fall, triggering the release of the uterine lining—your period.
So, if you do not ovulate, the estrogen build up of the lining continues, but without the usual ovulation associated progesterone. Thus, the hormone levels don't decline, and the lining stays up inside the uterus—your missed/super late period.
Alternatively, the built up lining can begin to shed on its own creating erratic bleeding patterns which are usually "too-light" or super heavy and prolonged.
There can be MANY causes for not ovulating: low thyroid, pituitary problems, ovarian cysts, physical stressors (eg sudden increases in exercise, crash dieting), emotional stressors (problems with partners, kids, money), increased body weight, anorexia, rotating shifts at work, etc. There is no specific linkage for pregnancy or C-section causing missed ovulations---unless one gained a lot of "baby weight".
steffie a new onset of pelvic pain can suggest a current ovarian cyst. Yet, if you have had this for 14 years, a cyst would not be the culprit. If you have not had your thyroid level checked that may be a good idea as hypothyroid can cause long term interference with ovulations. Cycles without preceding ovulations can produce much heavier flows which can lead to increased intensity of cramping. I would urge you to see your GYN or clinic about the increasingly severe cramping, they can also look for causes of irregular cycles.
Yours,
Jane