Ay, I totally get the worry even when you've done your research, pregnancy brain really does a number on us, diba! Honestly, if Body Shop confirmed na diluted na yung products nila and you've seen such great results na walang issues, I think okay lang talaga to continue using them, pero since you're still in first trimester, better to double-check din with your OB just para sa peace of mind mo, I did the same with a few products at honestly, parang nabawasan ang anxiety ko after confirmation from the doctor.
If gusto mo talaga ng something pregnancy-safe for the acne though, try looking into Mama's Choice Face Wash, Face Moisturiser & Face Serum, they're specifically made to be pregnancy-safe and breastfeeding-safe, and a few of us mums here in the group swear by them for pregnancy breakouts, so it might give you that extra confidence na walang worry talaga. But honestly, if the Body Shop one is working and making you happy, maintenance lang after the breakout clears up sounds like a solid plan!