I'm 25 weeks, wasn't active before my pregnancy and so far haven't been during. But now that it's warming up I've started walking a bit with the twin 6 month olds I nanny in their stroller. My question is, is it safe for me to start being active this late in pregnancy and if so how much is too much? I am overweight and I'm trying to avoid anymore unneccisary weight gain and make it easier to lose after baby so I can get back in shape, but don't want to put my baby at risk.