Mazal tov on the recent birth of your baby!
Cerazette is a progesterone-only contraceptive pill (“POP” or “minipill”). The minipill is an effective method of contraception when taken as directed. It is commonly prescribed for breastfeeding women since it generally does not affect your milk supply.
The minipill may cause irregular staining during the first 1-3 months of use. Therefore, if you are exclusively breastfeeding and there are no major medical issues that contraindicate pregnancy, we recommend waiting to start taking Cerazette until after going to the mikveh. This way, any staining from the pill will start once you are already tehorah, when it is much easier to deal with halachically. If you start it before you go to mikvah, staining may cause issues with the seven clean days.
For mikveh night and for the first week of using Cerazette, you should use a backup method such as spermicide or the sponge.
Once you are tehorah, you should take precautions against becoming niddah from any staining by wearing colored underwear or disposable pantyliners and waiting at least a few seconds (ideally 15 seconds) after urinating before wiping. Please see our articles on stains and toilet paper for more details.
You should also try to take the pill at the same time every day to try to reduce the chances of staining.
Please feel free to get back to us with any further questions.
B’hatzlacha!
This response has been updated to reflect the rulings of our current Rabbinic Supervisor, Rav Kenneth Auman, regarding waiting before wiping.