Okay so I'm 20 and my last period started on jan 11th..I'm about 2 weeks late rn. I had an annual check up about a week and half ago they ran a pregnancy test and it came back negative however they said it can take up to the first couple weeks in March for the test to show accurate results...what do you guys think ...could I be pregnant or are their other reasons that could cause a period to be this late ???

Ps- not on birth control