With my first girl 8 years ago - it happened to me. I was dreaming about getting up, going into the bathroom and peeing. Yup - it happened. Just a little but I shot out of bed and ran to the bathroom. Ewww. I too was trying to decrease my fluids before bed. It ended up that I was so tired that I wasn't waking to go to the bathroom.
I have strange dreams all the time. It's a common thing from what i've read. Before you go to sleep try meditating a little. For example, this about something happy. Like the time you got married, or your best memory with your mom or dad. And then think about your baby, heartbeating, and then listen to your own heart. Then think about your toes going to sleep, and then your legs, all the way up until you hit your eyes.
With my last pregnancy this is what my doctor told me to do. Clearing your mind of any fears will help you sleep better.
Good Luck!!