Mon.thly is an interesting new website. It’s a easy tool to help you keep track of your menstrual cycles.

Each time you start a new period, login and add the date to your Mon.thly account. After a few months, it will be able to predict given you past history when your next cycle will start. It will also act a a record of your menstrual cycles that can be hand for your medical reasons, or for your records. You can also set it to send you a reminder of your next estimated start date.

Mon.thly’s interface is super simple and discrete. A handy free tool if you like or need to chart your menstrual cycles.