I asked a similar question in the powerlifting forum since I'm interested in training for some amateur meets next yr.
From what I've found, Dr's have said there's really no way to prove you're on test, if you're within the limit and on a low dose. But... ethically speaking people look down on it since you're still priming your body, which can give you an advantage over people who may have test levels of 500 or something. Someone with test levels of 900 for example, has an obvious advantage.
It's not allowed, but really there's no way to test if you're on low doses of test. I would definitely stop HCG a week or more prior to the event though. Personally I don't really see it as cheating.