Can you use exposed acne treatment if pregnant?

Probably safe. Topical acne preparations are, for the most part, safe to use during pregnancy. Most do not have compounds that absorb into your body in significant enough amounts that would affect your baby. However some compounds, mostly prescription only such as Retin-A cream, and definitely oral medication such as accutane, have theoretical or real risks and should not be used.
Most likely. But if I have a pregnant patient come see me i would not treat as you cannot tell what can potentially lead to a pregnancy problem.