I would give it another couple of days at about day 15 and you haven't felt anything you might want to up the dosage. If you want to bump it up to 80mg a day I would go 20mg in the morning, 40mg pre-workout (about 45min-1hr before), and 20 mg later in the day.
I'm running it at 60mg split and I feel my muscles getting a bit harder...I may bump it up to 80mg or 100mg next time around.