Do not travel in AP if you have valid H1-b. There is no problem at all to re-enter US with AP, but you will get 1 year visa when you use AP to stay in US legally. So, until you have valid H1-b, you can use that one anytime to re-enter US, and my suggestion is not to use AP. I had exactly same case, I had both valid H-1b and AP , but i didnt use my AP just because my atorney told me not to use it until i have h-1b. goodluck.