Welcome to the STD forum.
There is no risk here. They call them STDs because you have to have sex to transmit or catch them (duh) -- and you did not. Although some people seem to think that STDs are merely infections that happen to involve the genitals and are easily transmitted, there is much more to it than that. If an infection could be transmitted by the sort of contact you describe, it wouldn't be classified as an STD. That's why things like staph, strep, common colds, and influenza are easily transmitted and very common in everybody, but things like gonorrhea, chlamydia, herpes and syphilis are not.
Here is another thread that explains the biology of it all in some detail; as you will see, the original question was much like yours. Start reading with the follow-up comment dated December 14.
http://www.medhelp.org/posts/show/1119533
Bottom line: No risk, no worries. Best wishes for the success of your studies in a beautiful land-- HHH, MD