NIPT Testing?

Andrea
Hi ladies!  Sorry if this has already been asked but I'm not quite 10 weeks and this twin thing is all very new to me.  My regular OB said I can go ahead and get the NIPT testing done, but my specialist seemed to say (without really saying) that it may not be very accurate for twins.  Then when I called the lab, they said my insurance company wouldn't cover it due to twins, but because of that they would offer me a reduced rate.  Is that because it's not effective at all on twins?  What is everyone's experience?  Sure I'd like to find out gender, but there's cheaper ways to do that.  Did anyone choose/choose not to get this done?  Any input would be greatly appreciated!