Before you take the plunge and decide to have unprotected sex with a fertile young lady with firm buttocks and breasts, you should really turn to your iPhone for advice and support. The App Store is full of tools that can track your partner’s periods (and this can be useful for other reasons, don’t forget) which is essential for discovering the best days to sow your seed. So where to begin?

Well you can start by disregarding any applications that have horrendous names, such as PeriodicRED, for example. You should also reject any paid-for apps, such as the £3.99 FemCal. Finally, you should spare yourself the queasiness by ignoring any application that goes into unnecessary details of flow rates and spotting days, such as Period Tracker.

My fertility calendar of choice is therefore the Free Menstrual Calendar that has a reasonable name, costs nothing, and doesn’t mention any kind of slow/medium/heavy/gushing flow scale. Furthermore, it even has the option to record ‘intimate relations’ which I find really quite amusing.