Windows 7 Ultimate Let To Activate On More Than 1 Computer?

I recently purchased a copy of Windows 7 Ultimate upgrade from my University who had them heavily discounted. I installed it on my first computer (which was running Windows 7 Home Premium) by doing a custom install (deleted all my partions) and it activated perfectly fine.

However, at the time, I didn't know that this upgrade was only for 1 computer at a time, so about 2 days ago I upgraded my laptop (second computer) using the same method as my first computer. I booted from the upgrade disc, selected custom install, deleted all the information on my hard drive, and proceeded to install. After installing, it prompted for activation, which worked perfectly fine.

I am now typing this message on my laptop (second computer) which is has windows 7 activated. My first computer is still at my university, and I am home for spring break so I will not be able to use that for a week or so.

I literally just found out that this upgrade can only work for 1 computer at a time and I heard that Microsoft will actually blacklist my first computer so that it is not usable anymore. Is this true? I am actually freaking out.. because that computer is my primary workstation and I need windows 7 to be working on it. Should I just uninstall windows 7 from this computer and install another operation system? Or is it already too late, my first computer is already broken?