License agreement question when it comes to developing in Unity Personal and then switching Unity Pro

Hi

I was just about to install Unity 5.2.1p4 and I decided to read the license agreement and I came across this:
"You May Not Use Unity Personal with Unity Pro or any Unity Pro Add-On Products

You may not combine or integrate Licensee Content that you develop with Unity Personal simultaneously with any Licensee Content that you develop with Unity Pro or any Unity Pro Add-On Products.  Licensee Content developed with the Unity Personal will be tagged with an identifier that is used to enforce this restriction.  "

So just to be on the safe side. Does this mean I can’t make a game in Unity Personal and then upgrade to Pro to publish it? It might be really obvious but I just want to be 100% sure.

simultaneously