Just wanted to put it out there. In the 6th month, maybe sooner, your hips and back might start to hurt, especially because you are supposed to sleep on your side. My sister got the most amazing pregnancy pillow for me for Christmas, and since receiving this, I have slept like a baby. Really :). It's not inexpensive, but it IS an answer to getting blissful sleep.
If you look at the video on this link to the actual site, it apparently is something you can use after the baby is born.
Here is what the wonderful pillow looks like: (and yes, it will add a third person to the bed...my husband is just very patient and understanding.)