If this is your first ultrasound, your dates may be off. Everything may be fine, but you need to do another one later to make sure. If you see a heartbeat then, rejoice! If the news is bad again:
If you have already seen a heartbeat and now there is not one, or if your second ultrasound confirmed an early loss, I am so sorry!!! I wish I could put my arms around you and pray for the Lord to comfort you. Thinking carefully about what to do next can really make a difference in how you recover.
Don't feel like you have to be in a rush to make a decision. Many women are rushed into D&C and have second thoughts afterward. There is no hurry at all unless you are hemorrhaging. Many women have waited weeks with no consequences.
If seeing the baby and burying it is important to you (and many, many women don't realize how important it is to them until it's too late because they were too numb to make decisions and were rushed), then you may want to opt for waiting for a natural miscarriage. At the very least, you should make it very clear to your doctor and the hospital that you want the remains if you have a D&C. Some are helpful with this, many are not. Contrary to what some hospitals say, you need no special permission to take the remains of a baby that died before 20 weeks (in most states, this may vary a week or two) or to bury it. Please don't miss this just because you think it will be gross - it really isn't and helps many women.
If you opt for a natural miscarriage at home, you may benefit from talking to and consulting a midwife. The midwife in my area was far, far more helpful, informative and resourceful than my very good OB. Also, if you've consulted a midwife you'll have someone to call if you have questions or difficulties whose automatic answer is not going to be "go to the hospital."
If you don't want to wait at home, or to have a D&C, there are meds the doctor can give you or herbs the midwife can, to induce your body to go ahead and labor, either at home or at the hospital.
If you are a friend or a relative of someone in this position, particularly if they are waiting for an ultrasound to confirm a loss, it is hard to support her, because I'm certain she doesn't want to talk about miscarriage right now. However, if she goes into the doctor without thinking over her options, she may get railroaded and have a harder time emotionally recovering. Pray you'll have the wisdom to know how to talk to her. Maybe even to just say, "I really recommend you don't make any decisions there at the doctor's office. Many women regret the decisions they make in a hurry like that."
I hope that helps some :-(