I-140/I-485 & chnage job

I filed I-140/I-485 petition concurrently eight months ago, but both I-140/I-485 have NOT been approved (i.e. pending status). Rigth now, I'm wotking with EAD. I heard that I can change my job SIX months after I-485 was filed. It that true even my I-140 is still pending? Anybody can help me on this?

Many many thanks.