Dont do it
..and gunshot wounds.
Personally, I would only tell my dr if I were having a gear related illness or injury..but then I'm paranoid.
You're not paranoid at all bioman. Most(generalization) doctors are uneducated/undereducated in performance enhancing steroids use, and only know the "bad things" that are hyped and propagated by the media and the government(even though the DEA and AMA were against making steroids class 3 drugs:see this interesting post
http://anabolicminds.com/forum/steroids/63118-hbo-real-sports.html ).
So as bioman wrote, unless you are having issues directly related to steroid use, ie: high blood pressure, bad cholesterol, problems in your blood work, possibly major surgery or a serious illness that you didnt have before, then NO dont disclose anything to your doctor, theres no reason for that information to go into your medical history charts, and god knows what kind of care or treatment an hmo/insurance company would try to deny you if, god forbid, you developed something they could try to link to your unsupervised steroid use.
This is just my opinion, take it or leave it.