You've completed the PH3 trainer, which means you may be thinking, "Now what?" If you really enjoyed doing this trainer, then by all means keep going with it. Plug your new 1RM into the calculator and start over in Block 1.
If you feel like you need a more serious goal, you can sign up for a powerlifting competition to test your new strength against other powerlifters. If you'd like to do something new, try one of Bodybuilding.com's other free trainers.
The only thing you're not allowed to do is to sit back down on the couch!