Ovulation is very tricky to pinpoint. Every person is different, and ovulation can be affected by external factors like stress, diet or medical conditions like PCOS (Polycystic Ovary Syndrome). Even if your menstrual cycles seem regular, the ovulation date is unpredictable and could come at any time during your cycle – as well as sometimes changing between cycles.

Long story short: you may be fertile at almost any point during your menstrual cycle (yes, even when you are on your period) and unprotected sex at any time of the month is not a good idea when trying to avoid an unplanned pregnancy.

Fertility tracking is not a reliable form of contraception – even if your cycles are regular, there is a risk of getting pregnant at any time of the month (yes, even while on your period) if you are having sex unprotected. Ovulation is very tricky to pinpoint, can vary from month to month and can be affected by a number of external factors.

Some people think that pregnancy starts when an egg is fertilised by the sperm. Actually pregnancy is defined as beginning at implantation: the moment a fertilised egg attaches itself to the wall of the uterus. So pregnancy can actually begin days after having unprotected sex.