Can a first response pregnancy test be wrong sometimes?

Possible: You could run another test to confirm it.

FIRST RESPONSE Early: Esult pregnancy test is reported to detect HCG up to 6 days prior to your anticipated period. If your HCG level is not high enough - then you will not get a + result (even though you may be pregnant). In that situation you can repeat in a week using your first morning void. Take care.