K.C.
I'm so sorry to hear this news and I hope it turns out to be wrong. It is possible and you should get a second opinion before doing anything medically to end the pregnancy. I know that earlier in a pregnancy, they can test hormone levels to see if they are changing/increasing as much as they should be with a normal pregnancy. Ask your doc if this can still be done at 10 weeks. In addition to looking for a heartbeat, have them measure the size of the baby. If it measures right around 10 weeks, that is a better sign than if it's only measuring around 7-8 weeks.
A very close friend of mine had two miscarriages (followed by a pregnancy carried to term). Her first baby miscarried naturally. With the second, she also had no heartbeat at an ultrasound, did a repeat ultrasound a week or so later, and did the hormonal testing. She was given some sort of drug (sorry, I don't know the name) that she took to induce the miscarriage. It was pill-form, I believe, and she took it at home. She had a fair amount of pain but it wasn't as bad as she'd been warned about and lasted for pretty much a full day. If you decide to try that, you probably won't want your son around the day you do it if you have an option for someone else to take care of him.
Again, I am so sorry you are going through this. I am glad you have a strong support group to help you through this tough time.