pg workouts...

For the most part, if you're already working out before you got pregnant, you can keep doing that as long as your doctor or body (or common sense) don't tell you otherwise.

Aside from that, just about anything low-impact is good. That can include:

Bellydancing (minus some of the more advanced stuff)
Yoga (highly recommend, even if you already work out)
Walking/Treadmill/Elliptical
Pilates
Swimming

Ditto on what Dragonwolf said!

I also have a lady in my Zumba classes that still does her jumping & lunges and some high impact stuff and she's maybe 4 mths pregnant...BUT she's been already doing zumba like a year, i think....Plus, she stops and rests when she feels the need...

It's how you feel...but don't start something if you've never done it before..just go with low impact....

If, later in the pregnancy, you're having round ligament pain when you power walk, etc., I found the full belly band to be GREAT help with that.