19 days menstruation delay but pregnancy test result was Negative (tested twice)

Hi mies. I'm 19days delay today. Done pregnancy test twice na nong 15days delay ako at kanina umaga, both result was "Negative". Last last week expected kong regla but at the same time nagkalagnat ako for just 3 days. Nabinat ata ako. Anyone here experience similar situation I have right now? Is there a need to worry na baka buntis ulit ako kahit 2 negative results yung PT. 9 months old pa lang baby ko.