I've been on growth for 5 weeks now, currently running 3iu's, and the past 2 weeks my knuckles on my left hand hurt. It's not bad enough to stop me from lifting but at times it does get in the way of gripping a heavy weight. The pain comes and goes only in my 3 finger on the left side. I started at a low dose and over the period of several weeks I worked my way up to 3 iu's. Is this a nautural side of growth???