More than 58,000 digital pregnancy tests have been recalled after some wrongly told women they were expecting.
Women who have bought the Clear & Simple test, manufactured by Guangzhou Wondfo Biotech, are being advised to return it.
The Medicines and Healthcare products Regulatory Agency "strongly encourage" women to report issues with the test, which has been distributed in the UK.
The specific lot number of the affected tests is on and inside the packaging.
- Description - Clear and Simple Digital Pregnancy Test
- Catalogue Number - DM-102
- Lot Number - DM10220170710E
- Expiry Date - January 2020
A recall notice from the manufacturer dated 1 September said this particular batch of tests was "producing a number of false positive results".
Dr Duncan McPherson, clinical director of medical devices at the UK's Medicines and Healthcare products Regulatory Agency, said: "Patient safety is our highest priority.
"We strongly encourage anyone to report any issues with this product, or more generally with any medical device, to our Yellow Card Scheme.
"If you have any questions about using digital pregnancy tests, please speak to your healthcare professional."
Positive results in normal circumstances are almost always correct, the NHS advises, while a negative test result is less reliable.