You really should think so...
Originally Posted by TheSoulz
Take a look at this question on Ask Ubuntu and its most voted answer. Also there are a couple similar questions on the right side under "Linked".
Why is “No new release found” when upgrading from a LTS to the next?
Steve Langasek Ubuntu Engineering Foundations team manager:
Then if you want to upgrade from 12.04 LTS to 14.04 LTS you have to use one of this commands:
Upgrades between LTS releases are not enabled by default until the first point release, 12.04.1, scheduled for July. It is recommended that most LTS users wait until then before upgrading to 12.04.
However as you can see by looking at the most voted answer to the question above you can force upgrade with one of this commands.
sudo update-manager -d
sudo do-release-upgrade -d