Do not put 3ml in one spot. Ever. It's not worth it.
Obviously the smaller the injection volume the lower the risk and the more comfortable itll be. Id rather people didnt do 2ml injections but I understand that not everyone has the extra 5 minutes it takes to do another shot.
Please just do this.
Whatever amount your weekly total is. Inject that much on the first day. Then proceed to do all the rest of the shots as normal.
If youre doing 500mg/wk, Inject 500 on sunday morning. Then 250 on wedneday evening. Then 250 on sunday morning, etc. That give you 500mg per week, every 3.5 days.