Why do I have very painful pain while in my menstrual cycle & also hurts when I have a bowel movement only when im on my cycle?

Endometriosis. Many possibilities dependng on if you have had sutgery before adesions and endometrosis an cause this best to be seen by your physician.
Endometriosis? Endometriosis can present like this - this means abnormal implantation of the lining of the uterus, the endometrium, in the abdominal cavity and on the intestines. When you cycle these implants can bleed or become irritated just like your uterus does, and can cause quite significant discomfort. I would suggest further evaluation of your hormones by your family doc or an ob/gyn doc.
Dysmenorrhea. Menstrual cramps often are mild and tolerable to most women, but some have vevry painful cramps requiring medical interventions. Often meds such as motrin/aleve (adequately dosed) will do the job, some requires more. The autonomic nervous system in your uterus area are similar to lower bowels and some cross-reactivities is often noticed, hence your pain with bm during cycle. Consult doc. Good luck.