Minecraft Nether Portal?

A buddy and I have built a Nether portal we arrived irgent where at the bottom of the Nether. When we came back through the portal, we came back to a different place than where we went in. We have set up our portal at the height of 7 has anything to do with it?

Did you build too close to another portal? Because that was the case with us. Our portal brought us in and the "neighbors" we always came out.

Nope