Welcome mscat
I'm guilty of not doing my pelvic floor exercises enough. I couldn't jump on a trampoline pre-pregnancy without weeing a bit, so god help me after baby number 3 
Well, after attending pregnancy yoga last week and loving it, I asked permission from my midwife to go again this week (as I have a low lying placenta) and the answer was no
I'm gutted. She said I can't do aqua natal either, no exercise allowed. It's actually scared me a bit, makes it all seem really serious as pregnancy yoga really isn't exercise at all, it's breathing and stretching.
I do quite a bit of walking, as I have 2 dogs (Labradors would you believe haha) and I'm worried now about doing too much now. I've got 2 kids, I lift stuff all the time, nothing too heavy but baskets full of washing, boxes of toys etc
We have another scan in just over a week (20 week scan again, at 23 weeks) and I'm really hoping my placenta has moved but my midwife didn't seem to think it will have, she said its more likely to have moved when we have the 34 week scan.