Positive Pregnancy Test Turn Negative Overnight

It can be a nerve-racking experience to take a pregnancy test, especially if you’ve been trying for several months without success.

It is even more disappointing if you had a positive pregnancy test and it turned negative the next day. Home pregnancy tests are supposed to be very accurate— for example, the First Response Pregnancy Test more than 99% accurate and the Clearblue Pregnancy Test is more than 99% accurate at detecting pregnancy if used on the day of the expected period.

Now, the question that arises is whether you’re pregnant or not. Is there an issue with the test? Did you take the test as recommended by the manufacturer?

Possible Reasons Why a Positive Pregnancy Test Turned Negative the Next Day

It can be very frustrating to have a positive pregnancy test today then a negative result the next day. We’ll look at some of the common reasons why this could happen.

A Chemical Pregnancy or an Early Miscarriage

A chemical pregnancy (also referred to as an early miscarriage) is one of the most common reasons why you may have positive pregnancy test result followed by a negative result 24 or more hours later.

A chemical pregnancy is more likely to go unnoticed and you would have your period normally. What happens is that after fertilization, only one third of fertilized eggs will be fit enough to complete implantation.

If the embryo does not implant itself in your uterus, it would die, and you wouldn’t even know that fertilization had occurred. Although implantation never occurs, a chemical pregnancy is strong enough to turn a pregnancy test positive.

A False Negative Pregnancy Test

You may be pregnant but the second pregnancy test turned negative because it was faulty and therefore didn’t work properly.

It is very unusual for this to happen, and if you notice this, you might want to check the expiry date on the box to make sure it is still effective.

If the test is still good for use, you should consider waiting before taking the test again. It is preferable you wait one week after your missed period.

A Very Sensitive Pregnancy Test

Thanks to continuous technological advancements in pregnancy test kits, there has been an increasing demand for self-contained and quick test results.

We now have access to very sensitive pregnancy tests that can detect the pregnancy hormone human chorionic gonadotropin (hCG) as early as six days before a woman’s missed period.

According to a previous study, the average concentration of hCG in urine nine days after ovulation (which corresponds to about five days before a missed period) is 0.93 mIU/mL.

Early-result pregnancy tests can detect very small levels of hCG in urine. For example, First Response Early Pregnancy Test can detect < 3.3mIU/mL, whereas EPT and Clearblue Easy Pregnancy Test can detect hCG levels in the 5.5–11 mIU/mL range.

Therefore, if you test shortly after conception, the level of hCG in your system will be very low but it can be picked up by a very sensitive test. If you test at different times of the day or drink too much water or beverages before performing the testing, you may have a negative pregnancy test result when the hCG concentration in your urine is very low.


I’m Princila, founder of Check Ovulation and a proud mom of two. I’m an alumna of James Lind Institute. After working in clinical jobs, my passion for writing took its toll, and I ended up switching careers to work in the medical publishing industry. I also have a passion for healthy food, which prompted me to take several online courses in nutrition and health offered by Wageningen University. (I still haven’t completed the courses thanks to my busy mommy schedule!). When I’m not writing/editing scientific and medical manuscripts or taking care of my family, I use my free time to research, learn, and write about healthy living. I have also authored a few books in the self-help niche using the pen names Princila Murrell or PN Murray.

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