PA first stretch

I got my Prince Albert piercing exactly 11 weeks ago, pierced at 10g with a circular "horseshoe" barbell made of implant grade stainless steel.

My eventual goal is to stretch upto 4g or 2g, whichever looks better.

It seems to have healed perfectly well by now, there's no pain or discomfort when moving it around, it doesnt feel tight even with an erection, and there is no bleeding/swelling/discharge/redness at all.

How much longer should I wait before initiating my first stretch (8g) to avoid pain or a blowout and stuff? Is it okay to attempt upsizing at this stage?