DNS problem, whois shows new servers, dig and soa nslookup show old older dns

I recently began migrating an old site to Drupal, and the hosting service I was using was really cheap and wouldn't have worked with all the modules I installed. I already hired a hosting account at a new (Drupal friendly) service and changed my DNS settings to point to their servers,... but the problem is that it's been a couple of days and the domain still points to the old account. When I whois my domain I can see in the domain servers section that the new servers show up, but if I nslookup or dig the domain I find the older s开发者_Go百科ervers. How could this be?

There are few possible reasons:

• Your ISP is still resolving you domain name to the old servers

• You have a local DNS server with a long TTL

• You have a record in your host file pointing to the old server

• The DNS change wasn't done correctly