First Trimester Abdominal Pains All Day Long

I am roughly 10 weeks pregnant and I feel nauseous and bloated and continually have slight pain in my abdomen all day long. I feel pain when I bend over, or sit cross legged; it seems I can only be comfortable when standing or lying completely flat.
I have had a miscarriage before, and this is my second pregnancy. Is the abdominal pain normal?
And should I be taking certain vitamins to avoid miscarriage?