Hi I did review your question and concern mam. your problem could be due to a functional problem which can be either Mitelschumerz pain, premenstrual syndrome or dysmenorhhea. i would recommend you to consult a gynecologist and discuss your issue in detail. Most important to be considered here is timing of your pain with your menses initiation. However, meanwhile whenever you have pain you can take Meftal spaz prn and keep a hot water bottle with tight knob over your lower abdomen as it can relieve the functional pain in many women with similar problems. I hope this helps Wish you a healthy life ahead.