Twins pregnancy. Need advise.

Dear Dr. OBGYN,
I had a ultrasound End of Nov. and from that and the date of my last menstruation, the doctor confirmed a twin pregnancy of 6 weeks then.
Dec 28th I went in for my second ultrasound (10 weeks since my last menstruation) and the technician could not find a heart beat of the twins and said the they measured a little over 5 weeks. That they may have stopped developing.
She suggested I go back in two weeks for another scan.

Could it be that I still have a chance? Or I will soon soon (or already have lost) the twins?

Gratefully for any insights,