Hi, I had some labs done. My hbg is 76 and my MCV is 120, what can it be?

Anemia. I assume you mean 7.6 for the hemogobin, which is anemia - too few red blood cells. The MCV is the volume, or size of the red blood cells. If the body doesn't have some key nutrients (b12, folate, (folic acid) etc) it cannnot put the cells together well and they end up large (mcv > 100). With iron eficiency the MCV is often low. Your doctor will probably start by checking those levels.