Dark jelly like discharge with pain at times to left lower abdomen, bloating throughout the month to point of looking pregnant at times, for12 years?

Complicated. It sounds like you could be describing endometriosis. This is where the lining of the uterus, (endometrium), may be outside of the uterus in small islands. It increases in size throughout the month just like it does prior to your menstrual cycle in your uterus. This would result in the bloating and talking about and also explain the dark jelly discharge you were having. See your ob/gyn doctor.