HELP/ADVICE

Advice needed, my last period was on the 19th December so it’s due again in about 10 days. Since Sunday I have been feeling so sick mainly on a morning so I daren’t have food until later on. I was thinking it maybe a stomach bug as surely this would be too soon to have any symptoms? When would be best to test as I have done one this week and obviously it’s negative but I can’t shift this nausea.