OK, thank you guys. I've started my cycle today with a Test Prop and Deca, after 3 months of strict deficit diet to loose fat. I've lost around 10kg ( and a little of muscle mass too unfortunately )

But now i'm around 16-17% BF and i can to start hoping to manage better estrogens.
Today i did first 100mg of Test Prop but i didn't take AI still. I will use Aromasin. My blood work is regular with a good profile ( i follow a perfect diet every day ). I'm going to stack with 300mg/week of Test Prop and 500mg/week of DECA for 10-12 weeks. I want to go careful with AI ( Aromasin ) as time ago i took it too much from the beginning ( 25mg/ED ) and i felt a shit since the same day i did the first shot of Test Prop; i did a blood work after about 6 days, and my estrogens was very very low! I decided to stop the cycle so, because i had to be very careful and healthy at work. Now i'm trying agan, and today after the first shot, i didn't take an AI and this time, i felt very well....
So i'm asking when to begin to take it and primarily HOW MUCH. I'm afraid to crash estrogens again...