Loading is only 2 days. You are correct on the length of P2. Some people say that you stabilize better if you do at least 30 days of P2.
P3 is when you add food back into your diet, excluding sugar and starches. P3 is for 3 weeks. P4 you slowly add starch and sugar with moderation to see how your body responds. P4 is 3 weeks as well.
You need to read Pounds and Inches. It explains the protocol in detail. Good luck!
I am here: http://tapatalk.com/map.php?psmjoh