Do I need EAD to work legally?

Hi, all,

I am J-1 visa holder and submitted my I-140/485 concurrently in this September. I didnot applied for EAD that time. I just heard a friend saying that J-1 holder will be in AOS (Adjustment of Status) when he or she submitted I-485 and so working needs EAD. Is that correct? Is it legal for me to work in the current position? My J-1 visa will expire in next August and I have not yet gotten the final approval result of waiver (Only the recommendation letter from US department of State). I just applied for my EAD last week. I am wondering what kind of status I am in. Your reply or suggestion will be greatly appreicated. Thanks in advance.