Usually you can get an early response test that will give you results up to five days before your expected period date. The ones that they use in the ob/gyn offices are the same ones that you can buy over the counter. There are not false positives on tests only false negatives. If you still think you are pregnant after a negative response you should try another test in 4-5 days. If nothing after that make an appt. To see your healthcare provider. You could have mis calculated your period, but there could be something else causing a lack of menstruation.

Ya go ahead and test now just dont stress if it is a late period stress or worrying could make it later