No heartbeat

I went for my 2nd prenatal.. We found out na walang heartbeat.. 11weeks lang xa kaliit na dpat 15weeks na xa.. My ob advice me to just wait na kusang lumabas ang baby.. But until nw wala padin im worried but sabi ng ob madami ndw cases na naghuntay lang din na hindi nman nalason.. I trust my ob but im still worried.. Any one here had the same experience?