K.S.
That sounds pretty miserable =(
I would assume the hormones of pregnancy and birth could cause the pre-existing condition (cysts) to crop back up. But also sounds like the symptoms of endometriosis.
There is also a condition called mittelschmerz which is what they call painful ovulation. Some opt to treat it and other extreme menstrual discomfort w/birth control pills. However, when it becomes "too much" the Mayo Clinic site recommends: "However, contact your doctor if a new pelvic pain becomes severe, if it's accompanied by nausea or fever, or if it persists — any of which could indicate you have a condition more serious than mittelschmerz, such as appendicitis, pelvic inflammatory disease or even an ectopic pregnancy."