I'm on contraceptive pills, period is 8 days late test shows negative, feeling nauseous most of the time?

Some basics: A properly done home pregnancy test should be positive in pregnancy as soon as a delay in the cycle is noted & definitely a week or more later. Some women occasionally skip a cycle & may see delays of a month or more. Nausea is a non-specific symptom of many conditions. Re-testing is an option as is looking for another cause of the symptom.