Closed Comedones!!

I'm using 0.025% A-ret Gel by menarini since the last 3 weeks. I use the gel 2 times a week once in 3 days at night. I have noticed increase in closed Comedones around my cheek area where I usually tend to get acne. I also use an exfoliating serum day before I use tretinoin. I am getting acne in the same area. Is this purging that I'm experiencing? Should I drop the exfoliating serum? Please let me know in the comments.