Everyones body is different. But I how ever have known many of woman to have full blown periods while pregnant. I woul try to take it a little easy though just to be safe. And if you become in pain should get to the dr..
Yes spotting can happen during the first weeks of pregnancy. If you go to www.babycenter.com they actually have an entire article on this. I love the site they have a ton of great resources for expecting and new mothers. Best wishes and congrats!