If you don’t know when you can get pregnant, then you’re cutting your chances of conceiving significantly! While men’s fertility is broadly stable from day to day – subject to a slow decline across a lifetime, and obviously affected by disease or toxins, like anything else – women’s fertility, their capacity to get pregnant, varies dramatically depending where they are in their menstrual cycle.
Pregnancy only has a chance to happen when sperm can encounter a fertile egg. This means that time in each cycle when you can get pregnant is defined by three things: the lifespan of sperm, the lifespan of the egg, and when that egg is ovulated.
Sperm can survive for around five days after ejaculation in the environment created for them in a woman’s body when it’s close to ovulation. After it’s released into the fallopian tubes, an egg is fertile for between twelve and twenty-four hours. This means that you have around five days before ovulation and one day after when sex can result in pregnancy. Outside of this, your chances drop quickly as only particularly long lived or fast-moving outlier sperm can reach the egg, and then fall to nothing.
To begin working when you’re next able to get pregnant (your ‘fertile days’) you need to start with ovulation. Finding out when your ovulation window will be gives you the foundation you need for the rest of your fertility planning. OPKs, or ovulation predictor kits test the hormone levels in your urine, looking for the key surge of Luteinising Hormone that cues ovulation.
This can give a clear result, but the problem is it doesn’t help you predict that cycle’s ovulation window, just confirm when it has happened. If you’ve got a very regular cycle, you can use that information to say when you’ll next ovulate – simply count back from your ovulation date to your period and take note of the of number of days. When your next period starts, count that number of days forward and mark your ovulation date on the calendar – but if your cycle is less regular you need a better solution.
You can monitor your progesterone levels with either a blood test, or with a specialist sensor that can monitor minute changes to your core temperature. If you can find an ovulation predictor that can work reliably with that data, it can interpret it not just into confirmation of when you have ovulation, but a prediction of when you will ovulate, as well as a wider prediction of when you will be fertile, giving you an advantage when you’re trying to get pregnant.