Use your transilluminator. If you don't have that yet (which I'm guessing you don't since you graduate in 2014), then just get a cheap penlight until you do get the transilluminator. Pointless to buy a nice penlight.
I would use your transilluminator. At least that's what the preceptors in my Clinical Methods I class recommends. They told us that if you're in a pinch, then you can use a pen light, but it's best to use your transilluminator.
About 50% of the class has gotten them so far, we had the option from several different distributors and they are coming in at different times. The clinical skills lab at PCO has diagnostic kits for us to use until then in every bay.