What are 4 Reasons for Late Period Negative Pregnancy Test?

Have you taken a pregnancy test after a late period and still got a late period negative pregnancy test? If your answer is “YES”, these are some of the questions you may be asking. Is there a chance I’m pregnant? If yes, why do I have a late period? If not, why do I have a late period? Late period negative pregnancy test happens because of the 4 reasons that I’ll discuss in this post. Let’s get started…

Reasons for Late Period Negative Pregnancy Test

1) Miscalculation of your menstrual period

This is the most common reason for a late period negative pregnancy test. The perfect woman’s menstrual period cycle is regular and takes exactly 28 days. Most women don’t have regular cycles.


The menstrual cycle has two phases.

  • The follicular phase begins at the onset of menstruation and ends when ovulation begins. During this phase, your body produces follicle stimulating hormone (FSH) and luteinizing hormone (LH).
  • The luteal phase begins exactly after the onset of ovulation and ends when the next menstrual period happens or after pregnancy occurs. During this phase, your body produces estrogen and progesterone. It lasts for 13-14 days.

Let’s do some basic calculation and see how a menstrual period miscalculation can lead to a late period negative pregnancy test. Consider a woman whose menstrual period lasts for exactly 28 days, but her follicular phase takes 17 days and not 14 days as expected. Thus, if she did a pregnancy test at her expected due period date, she would be taking the pregnancy test 11 days after ovulation. In this case, she thinks it’s her due period date but instead she is doing it 3 days before. The 3 days can lead to a late period negative pregnancy test.

2) Implantation and pregnancy tests

Pregnancy occurs after successful implantation. This usually happens between 6 to 12 days after ovulation. You know that home pregnancy test tests for pregnancy by detecting hCG in the urine. In a real sense, hCG enters the bloodstream after successful implantation. So, if you take a pregnancy test before successful implantation, you’ll get a late period negative pregnancy test.

3) Pregnancy test using dilute urine

As we saw earlier, pregnancy tests rely on the presence of hCG to detect pregnancy. Using dilute urine may give you a late period negative pregnancy test because it does not have the desired concentration of hormones to show on a pregnancy test. That’s why manufacturers recommend that you use the first morning urine because it has the best concentration of hCG hormones.

4) Expired pregnancy test

An expired pregnancy test will give you a late period negative pregnancy test. The fact that it’s expired means that it cannot give you valid results, and this may be a late period negative pregnancy test. You must always check for the expiry date when purchasing pregnancy test kits. Late period negative pregnancy test should not worry you anymore especially because you have this information at hand. If you have a late period negative pregnancy test and may be you did not miscalculate your menstrual cycle and followed all the pregnancy test instructions, it is good to see a doctor for professional advice.

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