No heartbeat at 8.6 weeks

Elizabeth
This is my first pregnancy. Went in for my first U/S on 7/6/15 thinking I'm 9 weeks and hoping for a clear measurement. The tech couldn't find a heartbeat. She didn't say much,  kept apologizing, and had me wait to speak with my doctor. I was scheduled to see my doctor the next day (today) and she explained to me that I'm having a failed pregnancy and I have 3 options to handle it. 
I did a bunch of research on chances of it being a mistake or the baby was hiding but most cases were at 6 weeks that just seemed to have conception dates off. My LMP puts me at 13 weeks but I know that was wrong and my cycles are like 40 days so I calculated I'm at least 8 weeks. And according to my baby's measurements I'm 8.6 weeks. So the doctor said a baby that size most definitely should have a heartbeat. 
Anyway, I went home and decided on the D&C. I want to get it over with ASAP so it's scheduled for Thursday 7/9/15. I'm scared! I'm scared of surgery but I want this over with. Im also afraid of going through this again. Just wanted to share in case anyone else is going through the same thing and looking for similar situations.