I had unprotected sex 4 days ago. My period is due in less than a week. Is there anyway I can still get pregnant?

Yes... and even after you start your period... there are no universal "safe days".

I took a test today and it said no. Could it just be negative because its only been 4 days ?

4 days is way too early for a test to work... you'd want to wait a few weeks. It would be more accurate then.

Unless you are tracking your ovulation cycle... something that's a PITA to do, ask anyone with problems concieving that does it, you won't have a clue when your SAFER days are. They rarely coincide with your period.