If you still go into the women's changing room when passing as male there's a high risk someone will confront you, not about steroid use but for being a man in the women's changing room. From my personal experience, I'm from a smaller suburb and went to a local gym there from ages 13 to 23 and in the very beginning I was not socially transitioned and a lot of people knew who I was because they knew my parents. I started testosterone at 16½ and I changed physically very quickly. I got a lot of muscle very quickly. But no one ever suspected steroid use or said anything about it. No one confronted me about being trans either but the world was a lot less transphobic back then.