You should be fine bro aromasin is pretty fast acting and aside all that it's not the most crucial thing ya know, it's not like ur just gonna blow up by having some estrogen in ur system while waiting on the aromasin to take its toll. This advice is me guessing that you are worried about water retention due to higher levels of estrogen, now if you are not wanting ur levels to get high for other reasons that's a different story and if so state specifically what your concerns are.