Knowing your menstrual cycle is extremely important for couples trying to conceive (TTC). The important question you need to ask yourself is, “ When will I ovulate? ”. Once you know this date, you can work out when you are most fertile and should start trying to conceive or indeed wear protection, depending on your goal. However, finding your ovulation can be difficult, especially if you have irregular cycles. In this blog post we wanted to explain how Natural Cycles can be a useful tool to track fertility and stay on top of cycle variations.
Let’s start with the basics.
Ovulation day is when an egg is released from the ovary and is available to be fertilised by a sperm. As sperm can survive inside of you for up to 5 days this creates a 6 day fertile window, which is the period a woman can get pregnant. However, the likelihood of becoming pregnant is dramatically increased if you have intercourse in the three days leading up to and including ovulation. If a woman has sex on any of these three days, she has a 27-33% chance of becoming pregnant [REF: Wilcox, A.J. et al. NEJM (1995) 333:1517].
A good first step to get to know your cycles and find your fertile period is to know how long it is on average. Day one is the first day of the menstrual period and the last day is the day before the next period begins. A general rule is the longer your cycle is, the later your ovulation day will be. For instance, my cycle is long with 33 days between periods with an average ovulation day of CD 21, which means my most fertile days are CD 19, 20 and 21. If you have shorter cycle, say 21 days between periods, ovulation is likely to happen on CD 7 and your highest chance of getting pregnant will be on CD 5, 6, and 7.
However, these days are never set, especially for us irregular ladies. Have you ever noticed your period coming earlier or later than usual? Or ever wondered why your pregnancy test is negative even though you have no period? Well, it’s because a woman’s follicular phase, the first half of your cycle before ovulation, is often variable – my follicular phase can vary up to 6 days! What this all means is that your ovulation day can differ from cycle to cycle, which is why it is good to keep track with an ovulation app, like Natural Cycles. With a clear rise in temperature and a positive ovulation test (optional), ovulation can be confirmed and your fertile window is mapped for your upcoming cycle, which are indicated by red days. TIP: It is important to measure as much as possible in the week leading up to ovulation to ensure that we capture any variations!
Another popular question women ask about their cycles is, “When will I have my period?” or “When should I take a pregnancy test?”
Let’s review the second half of the cycle: The Luteal Phase.
This is the infertile stage of your cycle and is pretty consistent (usually around 12 to 14 days). This means it is a useful menstrual cycle characteristic that can be used to determine when you are likely to get your period, which is approx. 2 weeks after ovulation. However, you should know that the length of the luteal phase can also be quite individual and can vary between 6 and 18 days, so you should never assume that your ovulation day was two weeks prior to this. Instead it is much safer to calculate ovulation with reliable fertility indicators, such as temperature and ovulation prediction kits (OPKs), like we do.
Once Natural Cycles has detected your ovulation day it can accurately determine when your next period is due so you can keep calm and carry on!
Period trackers, which are based on the rhythm method, assume you are regular. Their primary goal is to let you know approximately when you can expect your next period, which will be around the same time each month as they do not detect ovulation or variations from your data. However, Natural Cycles, gets to know and adapts to your cycle no matter what shape or size it is, calculating your unique ovulation day each cycle giving you an accurate idea of when your period will come (variations included) each month.
At the end of your Luteal Phase, when you get your period, your temperatures will drop down again and the app will let you know a new cycle begins!
Pregnancy tracker – plan users
Women usually take a pregnancy test from the first day of their missed period but not many know that the earliest point a woman can take a test is after the egg has been implanted in the endometrium at around day 9. It is fairly easy to recognise when you are pregnant if you are regular and know when your period is due but as mentioned before, if you are not, your period date could vary according to the length of your follicular or luteal phase each cycle.
Natural Cycles is a great tool for women that are planning a pregnancy, as it can determine from your data whether or not you have become pregnant! At the end of your Luteal Phase, if you don’t get your period and your temperature remains high (above the cover line) – the app will recommend that you take a pregnancy test to confirm it’s true.
If this is the case and you are pregnant, your temperature data entry dots will turn blue on your cycles chart.
As part of fertility awareness week, our next blog post we will talk about how fertility tracking can help you understand your reproductive health. Ask yourself, does your period come too often or maybe it doesn’t come at all? Find out answers next week or if you want to know sooner please get in touch with email@example.com or visit ask.naturalcycles.com
The Natural Cycles team