Hi. Thanks for asking in Healthcare Magic. The triphasic pills are supposed to mimic the normal menstruation. Trisprintec contains the same concentration of ethinyl estradiol, the estrogen in all the 21 active pills with steadily increasing dose of progesterone, norgestimate. This resembles what happens in a normal menstrual cycle. The total pills are 28 of which 21 (grey, light blue and blue) are active hormonal and 7 white pills are non hormonal pills. You could skip the white non hormonal pills and can post pone your period by reversing the strip and starting with 3rd week blue pill and giving a gap of one week for the menstrual cycle. But this is usually not recommended and the continuous high dose of progesterone can result in severe nausea, headache, mood swings, depression, abdominal bloating and cramps. So please consult your treating Dr. before doing so. I hope this helps.