Fetal pole growth good sign?

I don’t even know how far along I am at this point due to PCOS and long cycles. Maybe 6-7 weeks. I had an u/s last Monday and they saw a yolk sac and fetal pole but no heartbeat. Went back yesterday and still no heartbeat. However the yolk sac and fetal pole did look larger like my baby is growing. The u/s dr didn’t even look at my pics when he came in and already said that it seems to not be viable and started talking about miscarrying. I have had no bleeding. Slight cramps on and off but they have pretty much all together subsided and my ob told me that’s just my uterus shifting. My question is has anyone experienced this? Is the growth a good sign that we will see a heartbeat sooner or later? God I hope so. I am so anxious and nervous.