don't worry. standard employee drug screens only test for 5 different things. A/S is not one of them.
i think the 5 are: narcotics, amphedimines, opiates, pot, booze.
you'll be asked to fill out some paper work when you get to the office to have your test done. it will state on that what you are being tested for. gear won't be one unless your employer asked for it to be tested for. but i highly doubt that.