why don't you apply AP from

local immigration office? since your father is ill now, you can get a proof of your father's heath condition from his doctor in China.and bring that letter together with your I-485 receipt to the local office. I am in the same situation as you, but I am waiting for the receipt of I-485, once I get it , I will go to the local office to get AP.By the way can you tell me how soon you got your I-485 receipt after you filed it? I am also anxious now.Thank you!