I'm 12 wks preg with twins & my 10 wk us was good. i just tried to look at them with my us at work & could not see the deeper twin. is that bad?

Unknown : you mention that your ten wren soon was good. I assume that done by a professional under the guidance of your doctor. You mention a 12 week ultrasound being done at work but did not say who was doing it, their level or training or the equipment being used. Schedule a follow up with your doctor to verify all is well. Ultrasounds should be done under their guidance and supervision