Could you be pregnant if a pregnancy test came out negative but your period is 3 days late?

if your only 3days late than its too early for a at home pregnancy test to detect if your pregnant or not.Also not eating correctly or not eating enough can mess ur period up. Sometimes just having sex can mess your period up too. You need to be atleast 2 wks late for it to detect if ur pregnant or not. Go to ur local health department or go to a doctor to get a blood test so you will knw for sure.