Many choices. Women with thrombocytopenia, or a low level of platelets in the blood, may be at risk for heavier periods. Birth control options that are known to decrease bleeding include depo-provera (an injectable contraceptive), and the Mirena (levonorgestrel) iud. In addition, remember that polyurethane and latex condoms are safe, prevent pregnancy and STDs and don't have any side effects!
Anything. Anything they want.