hi i think you should read this link it may help you if perhaps late but please read it. the link <link> hope this helps. good luck
what is my risk of pregancy when i switch the pill to a different brand with different hormones. was on viorele for about one year (desogestrel and ethinyl estradiol) but recently switched to altavera (levonorgestrel and ethinyl estradiol). i have just completed the first packet and am on the inactive pill. four days into these my period is late and i have had sex in the past week. previously i would have expected to have had my period start about now. is the lateness due to the switch and my body adjusting or has the switch in hormones increased my risk of pregnancy?