Am I pregnant?

I have not had a period since the 19th of feb done home test and it was negative

if you had unprotected sex then yes its possible
you can get a blood test done at the doctors or try a different brand of pregnancy test if your still worried

Usually home tests are pretty accurate, but if you're still unsure, see a doctor.

Just go see a doctor.

Do another test and see a doctor regardless. It's not normal to go that long, and there could be an underlying problem.