A.F.
Naproxen is like ibuprofen (Advil) - it's an anti-innflamatory. Your cramps come from your uterus contracting and relaxing - an anti-inflammatory will help more than acetometephin.
Midol contains acetometephin (for pain), caffiene (for fatigue), and a diuretic. Midol doesn't have special pain medicine that targets cramps, specifically.