Good for you and I know it was thrilling. Keep it up and soon it will be normal wear. When wearing bras always wear ones with the adjuster in front, not too tight that causes bulges under your arm pits that would be visible when bending over, underwires are ok depending on the cup material with no bunching and should lay flat and straps should be small and thin.
No one will notice unless they put their hand on you which shouldn’t happen. Sports bras without formed cups are great stealth bras but know they can’t be removed without taking your shirt off because they go on over the head without band clips. Bralettes are pretty, and stealthy too but not quite so much as sports bras.
For tops wear something loose maybe a size larger than normal. Patterns and certain colors will help hide any lines. I have worn womens pastel tees many times without a problem.
Be careful and stealthy and you can feel girly all day long at work. Have fun!