When you say the pain is at the end of your collar bone, are you talking about your a/c joints?
If so, I get the same thing. My right was injured in a lifting accident some 17 years ago, and needed surgery to fix. My left now, was giving me pain earlier in the Spring. Even just warming up with an olympic bar, without taking any Ibuprofen, it was like driving a nail through it. I had it checked, and it's osteo arthritis. Apparently it's very common among guys who bench press for years with heavy weight.
Funny thing happend though. I bought 1-test and 4ad and mixed up the transdermal mix suggested here in the PH forum and within 2-3 weeks all pain subsided! I kid you not. Prior to the cycle I talked to my doctor about scheduling surgery just last August because even pulling a t-shirt over my head was painful. I even thought about holding off on the cycle because I was concerned about the pain I experienced doing just about every upper body exercise. But I cancelled surgery and have no plans of rescheduling at this point.
I asked my doctor about it, and he indicated that androgens are similar in structure to corto-costeroids, and that they might have had an anti-inflammatory effect.
Now I don't pretend that either the cycle, the dmso, or both has "cured" the arthritis. But I'm approaching, I don't know, 7 or 8 weeks post cycle. My strength is still way up, and my shoulders feel good, and frankly, I'm not even thinking about surgery any longer. Hopefully it will last
I know of one AS power lifter in his 40's who experiences similar benefits of cycling as well. I wonder if anyone here has "enjoyed" this additional benefit as well?
Also, I've read that the ONLY place we should be lowering the bar on the bench press down to is the bottom of the chest. Any higher only invites rotator cuff damage and puts more stress on the a/c joints as well.
Good luck.