pinkdemoness,
I can't wait for my swimsuits to arrive as I have bought from Old Navy. Once arived, I will plan to start at least weekly swims. I am in my 13th week, going 14th... So has passed 1st trimester, i think it is safer to start from 13th week onwards bah. You might need to check with your gynae in regards to exercising, some preggies' conditions might not allow for exercising. I think also better to avoid Jacuzzi bah and hot bath - see below extract from an article:
"When you use a sauna, jacuzzi, hot tub, steam bath or steam room, your body cannot lose heat effectively by sweating. Your body's core temperature therefore rises. If you're pregnant, the amniotic fluid in which your baby floats can also start to heat up. Some evidence suggests that a significant rise in your core temperature can cause birth defects. For example, to your baby's developing nervous system.
When you're pregnant, your heart and blood vessels are already working harder, to support your developing baby and expanding womb. If you overheat, the demands on your heart and blood vessels will increase further. More blood flows close to your skin, to help cool your body by sweating. Therefore, less blood flows to your internal organs. If there isn't enough blood flowing to your brain, it could make you feel faint (when you feel weak and unsteady before passing out, usually just for a few seconds)"
(Catherine Lynch, ob-gyn, director of the division of general obstetrics and gynecology, University of South Florida, Tampa )
Hot tubs are usually too hot to be safe for pregnant women to use. We know that water over 105 degrees is damaging to developing cells. It won't damage yours, but the baby is sitting in fluid that's also going to get very warm. And extreme temperatures can damage early embryos. So hot-tubbing in the first trimester could cause malformations in the fetus or cause you to lose the baby.