Baby measuring smaller (6w3d vs 7w3d) with no heartbeat

T2 • 37 TTC# 2! Have one beautiful happy 13 Months Baby Girl!
Hello Ladies! We did a <a href="https://glowing.com/glow-fertility-program">IUI</a> on the O date and got pregnant! I had chemical before this and this is our second pregnancy! I'm 35 and been ttc for 8 months! I went for early transviginal u/s as my hcg wasn't double every 48 hours rather it was going up by 60%! We did 2 u/s do far, one at 6w2d where the baby was measuring 5w6d with only gestational and yolk sac visible! Then on my 7w1d we went for 2nd u/s where the baby measued 6w3d with a feteal pole visible this time! Both the times no fetal heartbeat was visible! The doctor is not hopeful and advising on a) wait out for natural mc, b) medicine induced mc or c) schedule a d&c! 
I can't bring myself to abort the pregnancy as  part of me still believes the baby will make it! I have scheduled another u/s this week and gave myself 2 weeks to make the decision if the nature don't take before that! Please ladies tell me I'm not crazy to think like this! Please let me know if you have experienced something similar or heard about it?