Pivot Point Issue.

Hi guys so Im currently working on creating a block out for my level and i’ve stumbled upon what seems like a simple issue yet I haven’t been able to find a solution online.
So basically a while ago when I was rotating meshes around, the pivot point would rotate with the mesh so it would be quite easy to align meshes next to each other. I’m not sure what i’ve done but now the pivot is set at an angle and placing meshes next to each other is quite difficult. Any idea how to solve this?
Here’s a screen shot.
1 - The first image shows a box that ive just placed in the scene, as you can see the pivot point is aligned with the faces of the box.
2 - On the second image ive rotated the same box and the pivot points rotation has remained in the same direction. (Earlier this was not happening.)