You have not mentioned that the steroid which you used was a anabolic steroid or you have taken steroid medicine as life saving drugs. If you have taken anabolic steroids in low doses for a week then it may not damage your normal process of spermatogenesis but if you continue to take low or high doses of anabolic steroid then it can cause reduction in the normal sperm count and not able to fertilize egg. So don't take it for longer duration. One week is sufficient.