Pregnancy

Hi mummies asking on behalf of my fren.. Just want to know if you've missed your menses for the month and did pregnancy test but stated negative for her.. So does that mean she's preggy but still early to detect or menses delayed case.. Since it's her 1st time missed menses for about 1 week.. So she's confused of her situation.. She did test with UPT but it shows negative results.. What she has to do further.. Wait and test again??