Retin a from a 0.01 to a 0.25?

Ive been using a 0.01 % gel for four months which worked ok with no adverse reaction. My doc has now changed it to the 0.025 % and my face and neck have produced more acne again not major but more than before I also have some mild red rough patches on neck. I assume this is usual but would like to know for sure. Thanks in advance for your answers!!