EAD and H1 visa

May I apply EAD, and don't use it unless it is necessary? My I-140, 485 pending, I am looking for a job now, but I am not sure if I could get one in time, my attorney suggest me to apply EAD, I don't want to
give up my H1 now ( the second years). I need you give me a idea. I was shocked when my boss told me I have to leave in three month.thank you!!