How long after 1 Fraxel dual/Clear + Brilliant combo will I have to wait to get a mixto CO2?

I just received a fraxel dual and clear and brilliant 3 days ago. I am considering doing a mixto fractional instead of continuing with 2 more fraxel/dual. I actually regret not doing the stronger laser first because I want to see noticeable results on my shallow acne scars even if I have to deal with some hyperpigmentation on my type 4 darker tone with retin a and hydroquinone which I have used to pretreat. So far I see no difference. How long will i have to wait now to get a mixto C02.