Pregnancy tests all work in the same way; they detect the presence of a hormone called human chorionic gonadotropin (hCG), which your body releases into your urine not long after conception.
Pregnancy tests are coated with a chemical that contains antibodies that will bond to HCG if it’s present in the urine. This bonding will give a positive result on your pregnancy test. If there is no HCG present in the urine, no bonding will occur and the test will be negative.
How do Cheap & Expensive Pregnancy Tests Differ?
Cheap tests have the bare basics – the chemical required to give a positive test result.
Expensive tests have the same chemical to give a positive test result but also come with extras, such as faster results, more information (such as how far you are) or easier to read visual results (ie, lines that may be darker).
So Do Cheap Tests Work Just As Well?
Yes, cheap pregnancy tests will give you the exact same answer because they test your urine in the exact same way, by checking for HCG.
However some more expensive tests may be more sensitive (give results sooner) than cheap tests. Both types of tests can give false negatives but rarely give false positives.
The only way to definitely tell if you’re pregnant if you’re not sure is to talk to a doctor and have a blood test.