Periods

Okay so my period still hasn’t came I took a test when I was a day late and it said neg * it was a dollar store test * .. and it’s only been 2 weeks since I had ovulated ? I’m cramping .. & super tired ? I’m supposedly 4 days late on this app ! I usually come on around the same time every month ? And I know my exact symptoms so it’s kind of off but the test said neg ?