TTO ? - how safe for continued topical use?

So, last night, after I woke up with my shoulder in a big bunch o' pain, I took some advil and decided that instead of icy hot (which I used up on DH... j/k - which we never have) I'd put a few drops of TTO into some lotion.  Somehow, either through the power of suggestion, or by actually increasing blood flow or something, it really helped.  My shoulder, which was by far in the worst pain was pretty much pain free when I woke up, while my other muscles were worse. 

I used it on some of my other sore muscles, and, again, either by confusing its results with the fact that I was just up and moving around a bit more, it seemed to help.  

So - any problem in continuing this?  Am I cracked?  Hm?