Any 2nd time mommies??

I am currently 6 weeks pregnant with my 2nd but I have a 1 year old daughter who keeps me on my toes! She plays rough and loves to jump on my tummy. How can I keep her from being so rough? The only way to keep her still is to strap her in a seat or put her to bed which I can't do that all day. I definitely don't want to lose the baby, but I feel so much pressure on my stomach and I've been cramping badly but it seems to get worse after I've been chasing her, picking her up repeatedly, and her trying to jump all over me.. what to do? How do you cope with an active child while pregnant?