Written by Rhiannon Davis. Reviewed by Jenny Wordsworth. 

Navigating pregnancy testing can be tricky if you have irregular periods. The timing of a test can feel uncertain, and it’s easy to get frustrated if your cycle doesn’t follow a predictable pattern. But there’s good news: you’re not alone, and there are ways to better understand when to test, even if your periods aren’t regular.

What Are Irregular Periods?

Irregular periods are cycles that vary in length from month to month. This means that your period may come earlier or later than expected, or sometimes it may skip altogether. Factors like stress, weight changes, hormone imbalances, and certain medical conditions (like PCOS or thyroid disorders) can cause irregular cycles.

Whilst the average cycle length is 29.3 days, 65% of people have cycles between 25 and 30 days. If you’re actively trying to conceive, it can be frustrating when your cycle isn’t as predictable as you'd like it to be. It may feel like your body is working against you. But with the right knowledge, you can take control and feel more confident in when to test.

How to Track Your Cycle

Even with an irregular cycle, it’s still possible to pinpoint when to test for pregnancy. Tracking your cycle is key. Here’s how:

1. Track Ovulation: Start by trying to track when you ovulate. You may not have a regular cycle, but ovulation will still occur roughly halfway through your cycle, even if the length varies. Tools like ovulation predictor kits (OPKs), basal body temperature (BBT) charting, and cervical mucus monitoring can help alongside using a cycle tracking app like Clue (in Conceive mode).
   
   

2. Understand Your Luteal Phase: After ovulation, the luteal phase (the time between ovulation and the start of your period) typically lasts 12–16 days. If your period doesn’t arrive within this timeframe, it could be a sign that you're pregnant, and it might be time to test.
   
   

3. Use a Longer Window for Testing: If your cycle is irregular and you’re unsure when ovulation occurred, give yourself a bit of extra time before testing. Wait at least 14 days after suspected ovulation to ensure accurate results.

How Early Can You Take a Pregnancy Test?

If you have irregular periods, timing your pregnancy test correctly is crucial. Here’s a general guide:

• First Day of Missed Period: If you’ve missed a period entirely, it's usually safe to take a pregnancy test. However, if your cycle is irregular and you aren’t sure when your period is due, it’s best to wait until you’re at least 14 days past ovulation (DPO).
  
  

• Early Tests: Some pregnancy tests, such as OVUM’s, can detect pregnancy as early as 6 days before your missed period, thanks to their sensitivity of 10 mIU/mL. While early testing is possible, it’s essential to note that if you ovulate later than expected, the results may not be reliable. Our test measures levels of the hormone hCG, which increases early in pregnancy, but testing too soon may still lead to false negatives.

• Late Testing: If you’re still unsure and you’re more than two weeks past ovulation, a test should give you a clear result, as hCG levels would have risen enough to be detected by most tests.

Understanding False Negatives

Irregular periods can sometimes lead to confusion, especially if you’ve taken an early test and received a negative result. Keep in mind that false negatives can happen. Even with a missed period, testing too early may not detect low hCG levels in your urine, especially if you ovulated later than usual.

If you get a negative result but still haven’t had your period, wait a few days and test again. You could also try a more sensitive test (the current most sensitive test available to purchase is 10 mIU/mL) or consult with your GP. 

When to See a Doctor

If you’re struggling with irregular periods and have been actively trying to conceive for a while, it might be time to talk to your GP. Conditions like PCOS, thyroid issues, or other hormonal imbalances can contribute to irregular cycles, and your doctor can help pinpoint the cause.

It’s also worth seeing a doctor if:

• You have been testing regularly but haven’t received a clear result.

• You experience irregular periods and other signs of potential fertility issues, such as extreme pain during your period or difficulty getting pregnant.
  
  

Your doctor may suggest fertility testing or refer you to a specialist for further evaluation.

Key Takeaways

If you have irregular periods and are trying to conceive, it can feel like an emotional rollercoaster. The good news is that with the right tools and knowledge, you can gain a better understanding of your cycle and feel more confident in your testing. Don’t hesitate to consult with your GP or a fertility expert if you need more personalised advice.