Understanding Ovulation

By The babystart® Team · General information · 6 min read

If you're trying to conceive, ovulation is probably the single most important word in your vocabulary right now — and yet it's often the least understood part of the menstrual cycle. Here's a clear, straightforward guide to what's actually happening in your body, and how to use that knowledge to your advantage.

What is ovulation?

Ovulation is the point in your menstrual cycle when a mature egg is released from one of your ovaries. It's the single event that makes pregnancy possible in any given cycle — without an egg being released, there's nothing for sperm to fertilise.

In a typical 28-day cycle, ovulation tends to happen around day 14, roughly midway between the start of one period and the next. But "typical" is doing a lot of work in that sentence: cycle lengths vary hugely from person to person, and even from month to month for the same person. Someone with a 24-day cycle might ovulate around day 10, while someone with a 35-day cycle might not ovulate until day 21 or later. This is exactly why counting on your fingers from a generic calendar isn't a reliable way to plan around ovulation.

What is the LH surge, and why does it matter?

Ovulation itself isn't announced by an obvious symptom you can set your watch by. What triggers it is a hormone called Luteinising Hormone, or LH. In the run-up to ovulation, your body produces a rapid spike in LH — known as the LH surge — which tells the ovary to release its mature egg. Ovulation usually follows within around 24–36 hours of that surge beginning.

This matters for timing because the LH surge is the most reliable, detectable signal that ovulation is imminent. Rather than guessing based on calendar dates, symptoms, or how you feel, testing for the LH surge tells you when your body is actually gearing up to release an egg — giving you a much more precise window to work with.

How to identify your fertile window

Your "fertile window" is the stretch of days in each cycle when conception is possible. Sperm can survive in the reproductive tract for up to around five days, while the egg itself is viable for a much shorter window after release — generally less than 24 hours. Put together, this means your most fertile days are the day or two leading up to ovulation and the day of ovulation itself.

A few approaches are commonly used to narrow down this window:

• Cycle tracking — noting the length and start date of each cycle over a few months to spot your personal pattern.
• Physical signs — some people notice changes in cervical mucus or a slight rise in basal body temperature around ovulation, though these can be subtle and easy to miss.
• LH testing — using an ovulation test to directly detect the LH surge, which is generally the most precise of the three.

Used together, these methods can help build a clearer picture of your cycle over time — but for many people, testing directly for the LH surge is the simplest way to know, with confidence, that the fertile window has arrived.

Testing for your LH surge with FertilTime®

FertilTime® Ovulation Test is a simple, at-home mid-stream test designed to detect the LH surge, so you can identify your two most fertile days with confidence rather than guesswork. It's over 99% accurate, comes with 5 tests per pack so you can test across several days of your cycle, and gives a clear result in just 5 minutes — no lab, no waiting for post.