Patient: Switching from the combined pill to the progesterone only pill. While on the combined pill I generally don’t start my period until a few days after taking the last tablet of the cycle. Should I start the progesterone only pill the day after I take the last combined pill or the day I start my period?
Doctor: When changing brands of pills it is important that the pill-free interval is not prolonged. Increasing this interval by even one day, is associated with an increased risk of breakthrough ovulation and pregnancy.It is generally recommended that you start the new brand of active hormone pills and skip the pill-free interval (i.e. follow old combined pill tablets with active tablets of the progesterone only brand without a pill-free interval). This means that you will miss a withdrawal bleed for this cycle. if however you have already stopped the combined pills and are in the pill free week, I suggest that you start the new pack on the day you start your period and follow the 7 day rule. It means that you will need to use alternative methods of contraception, such as condoms and a spermicide until such time as 7 active hormone tablets have been taken from the new pack. This is to ensure that there are no chances of an accidental ovulation leading to a possible failure of the pills.Hope you find this information useful and are able to successfully stay protected.