No symptoms?

I've always heard with twins the symptoms are more intense...I've got nothing. I should be 6w2d but I went in at 5w6d and they could only barely see the yolk sacs. I'm worried about my lack of symtoms. Breasts had a minor amount of soreness and got slightly bigger but that seems to be leveling out. Every once in awhile I have some cramps but not even everyday and fatigue is rare when I do have it its very mild. Anyone else with twins and minimal symptoms?