I don't mean to scare you, but yes. I had two with no bleeding at all and my only symptoms were a lack of symptoms and cramping. I was really confused and everyone kept saying I was fine.
I hope this doesn't scare you... I also have two friends who felt the exact way as I did and one had a perfect pregnancy and delivered a healthy baby and the other is due in one month and has had no complications.

You should go to your doctor asap... Sometimes it is just a case of low hormones and they can help with that. If they say let's wait and see insist on an early ultrsound and lab work... One thing I have learned from my experiances is to take initiative and trust my instincts.

Good luck!!!

Miscarriage Symptoms
A miscarriage is the loss of a pregnancy before 20 weeks and it is nature's way of ending a pregnancy that is not developing normally. The length of the pregnancy will effect the number and severity of miscarriage symptoms.

A miscarriage that takes place shortly after conception can occur as a slightly late, slightly heavy period. Symptoms can vary from person to person, but there are common ones that generally occur:

Bleeding. This can range from brownish spotting to heavy bleeding. It is important to note that many women experience spotting or bleeding during pregnancy and about 50% of the time, the pregnancy progresses normally.
Pain or cramping in the lower abdominal area. The pain could be on just one side, both sides, or in the middle. You may also experience pain in the genitals, lower back, thighs, or buttocks.
You may notice that pregnancy symptoms like nausea and breast tenderness have subsided or lessoned. Be aware that some women do not notice any change in these symptoms, while others do.
Some women say that didn't "feel right" just prior to their symptoms.
If you are pregnant and experiencing symptoms you should contact your health care provider. If any of the following symptoms occur you should go the Emergency Room immediately:

Heavy bleeding
Passing clots or something that looks like tissue (bring the tissue to the hospital in a clean container)
A fever higher than 100.4 degrees F
Dizziness or fainting
A history of tubal (or ectopic) pregnancy
Severe vomiting
Severe pain the abdomen or back
If you have any uncertainty about the need to contact your health care provider, call him or her immediately.