10 weeks pregnant and been cramping on the right side off and on. What does this mean?

Round ligament pain. Assuming you have had a normal sonogram and are not having any bleeding, this is probably what we call round ligament pain. As the uterus grows it tends to pull and stretch on its attachments, but since it also rotates as it grows this will be more on one side than the other. See your doctor if the pain is severe or accompanied by bleeding, nausea, or fever.