An urgent warning has been issued for people who have bought Clear and Simple Digital Pregnancy Tests to check if they used one of the faulty products.
They are advised to check the lot number of the test and discard any others they may have bought.
Chinese manufacturer Guangzhou Wondfo Biotech issued a product recall affecting more than 58,000 pregnancy tests, the Medicines and Healthcare products Regulatory Agency (MHRA) said. It followed "a small number of false positive results".
The affected lot number is DM10220170710E. All should have been taken off the shelves and their use-by date was July 10, 2017, to January 9, 2020.
Concerns remain over people who may have stockpiled a number of the products at home to carry out future tests.
Dr Duncan McPherson, MHRA’s Clinical Director of Medical Devices, said: "It is important people check the lot number of any Clear and Simple Digital Pregnancy Tests they have purchased to see if they have a product from an affected lot.
“If you have any questions about using digital pregnancy tests, please speak to your healthcare professional."
In a statement the MHRA added: "Guangzhou Wondfo Biotech has announced that they are recalling one lot of faulty Clear and Simple Digital Pregnancy Tests following the tests producing a small number of false positive results.
"The lot number can be found on the end of the box and is also printed on the sachet. Only this lot number is affected.
"The manufacturer estimates more than 58,000 affected tests have been distributed in the UK.
"Anyone who has purchased an affected test is advised to seek alternative testing methods and return affected tests to their pharmacy or shop."