I was getting 70% AHA peels done at a plastic surgeon's office, and was told not to use anything harsh three days before and three days after the peel. But 70% is the strongest AHA peel available, so that is why. On the days that were not right before or right after the peel, I was prescribed Renova (basically Retin-A) and I used BHA and other AHA products all at the same time and didn't have problems.

However, everyone's skin is different so you may just need to experiment to see what you skin can and can not handle.