Is it possible for a pregnancy test to read unable read?

Pregnancy tests do not display the message "unable to read." Pregnancy tests typically display one or two lines to indicate the result. If the test line is as dark as or darker than the control line, the result is positive, indicating pregnancy. If the test line is fainter than the control line or absent, the result is negative, indicating the absence of pregnancy. Some pregnancy tests may also display error messages such as "invalid" or "invalid result," which indicate that the test was not performed correctly or that the result is inconclusive.