It is common to have severe cramps. It might be normal, but it might not. Some girls have endometriosis, which can cause the severe cramps and this condition can lead to infertility later in life. See a gynecologist who can offer you medicines for cramps if the cramps prevent you from doing normal activities you do easily when not having bleeding from your cycle. Another issue is irregular cycles. This is not necessarily a feature of endometriosis, but should be documented to see if you have another condition known as polycystic ovarian syndrome, which also can cause issues with weight management, acne, infertility, and diabetes. Many young women are just waiting in their normal hormonal brain axis to figure itself out in the first year or two after the onset of their cycles. See a doctor trained in menstrual irregularities so that you do not miss an opportunity to optimize good health.