Quick test to help determine that it is NOT a fracture....grab your pager....turn it vibrate mode and then place it on the bony aspects of you arm, wrist and fingers. Touch your arm with it while it is buzzing. Be thorough...make sure to put the pager anywhere you can feel bones in your arm and forearm. If at any point you feel twinges of severe pain, go to the ER. If you put the pager all over your arm while buzzing but nothing gives you a deep severe bone pain, then it's likely to be a soft tissue problem.
This test is similar to a tuning fork test the old medical doctors used to use to determine a broken long bone. The sound wave travels down the bone and if there is a cortical break, the broken ends rub together in a chattering fashion. Since bones are loaded with nerve endings on the surface especially, it will cause immediate discomfort as long as the bones are still vibrating (most people yell one or two curse words in cases of a positive test)...which is why it's not used anymore these days...it hurts too badly on a broken bone. But to keep you from being concerned about the value of this test, it would only hurt for a second or two.
If you think it is a soft tissue injury (ligament, muscle, tendon, etc.) then try moving the arm with your other hand (or having someone else move your arm around), while you keep the muscles of THAT arm absolutely still. Passive motion causing pain is an indicator of possible ligament sprain (potentially complicated by muscular strain). Of course, that's based on a negative pager test for fracture. If you have pain ONLY when you actively move THAT arm, but not when it is passively moved, then it is likely to be muscle or tendon strain.
If you can pinpoint which it may be:
ligament sprain--prepare to be out of commission for up to two months. Get evaluated to make sure it is not severe enough to require a surgical consult (I doubt it in this case since you worked out since the initial injury).
Muscle strain--give it a week and then see if you can handle a workout.
fracture--go to ER
***If you try the pager test and don't feel any pain that does not mean you DON'T have a broken bone, just helps to rule it out. The same goes for the passive and active motion tests. If there is any question about what the cause is, I'd have it seen to just in case. If you don't feel any better or if you experience throbbing arm pain or new symptoms go see the docs.