I am 18 weeks pregnant and worried because Ihave had 2 previous miscarraiges and am having low abdominal pain and pain feeling like it is steming from my vaginal canal. Is this normal? I don't think I have a bladder infection because I don't have any other symptoms.

It could be normal depending on the severity of it. Many women will have occasional cramping, aches and pains, and stretching in pregnancy. It is usually not a concern unless it is severe, continues for an extended time, includes bleeding, or starts to have a pattern to it.

Certainly since it causes you concern, let your doctor or midwife be aware. You can always ask for a scan or a listen to baby's heartbeat for reassurance.