2 days is fine with Homeopathic hCG. If you are taking real hCG, then three days is required.
If they're Homeopathic, you're good to go to P3 after 48 hours. In any case, you can certainly extend your P2 for as long as you like as there is no immunity issue with the hHCG. I think you should adhere to the pounds lost limit per pounds and inches, which I believe is 34 pounds lost. That will give you your best hope to stabilize in P3.
I did hhcg drops and went 40 days. Could have gone longer but just needed a break. I waited 48 hours, and went right to P3.