I have never had a child physically (my daughter is adopted), but because I have endometriosis, I have many years of experience with painful periods. Here are some things that have helped me:
1)Get on the top of the pain. Take the advil/tylonal/aleve (whichever helps you the most) right when you first start feeling the pain before it gets bad. Once you take the pills, jump in a hot bath~ as hot as you can stand it~ for at least 20min (gives the meds time to kick in). Gently stretch in the tub. This keeps the muscles relaxed. Once the muscles cramp up, you are fighting a harder battle. If you are not in a place that you can take a bath (like work), there are heat release wrap around throw away things you can find in a Longs type store near the heating pads.
2) Starting about 24-48 hours before you expect the pain and continuing through your period, alter your diet a little. Cut out salt (retaining water makes your body more uncomfortable), and no caffeine (stimulates muscles, you are going for relaxation). Eat things that are easy on your tummy so that your body isn't spending energy in the digestive area and can spend energy working on relaxing your muscles. Think whole foods and stay away from processed foods.
3) When you are off your period, look into doing some yoga type excercises. You can find books about yoga for menstral health etc. The stretches both help strengthen and relax your pelvis and back so that the muscles are more prepared for what is coming.
Good Luck!