Did I break a bone or did I just hurt my leg?

Yes it does take quite a bit of force and pressure to break the femur, although I have seen some broken from just a little pressure too. But since the beam caught you, you probably just bruised the bone. If you have broken your femur you would have been in a lot of pain after it happened and would most likely not be able to walk. But if this pain stays for more than say 4 days to a week get to a doctor and get it checked out.