I'm sure heaps of rah rah comments will kick in, but the simple way to see whether your muscle 'function' has been affected is do a strength test.
Do it strict, and legit, but strength test yourself.
If you see something like at least a 10% drop (pulling that number out of my ass), you've probably been affected and shouldn't go again till it at least gets back to normal (or supercompensates and bounces up a bit).
For biceps, a single arm preacher curl is a straightforward easy 1RM to do and see if things have dropped off.
The muscle being sore or not may not necessarily suggest anything, as muscle DOMS (delayed onset muscle soreness) could be from one of several quite disparate physiological mechanisms.
edit: if it hasn't changed (strength that is), then sweet, there should be nothing stopping you training again.