In truth not all positives show at 5 minutes, so wait longer to minimize chances of false negatives.
Use tests that are new, not near expiration date. Reasons for low positive result: maybe tested too early - wait until your period is 1 week late. A single positive result indicates pregnancy
. Near 30% of conceptions abort spontaneously in the first few weeks. Wait several days, re-test.
Answer assisted by Jin Packard, Medical Student