Ive had insomnia this whole pregnancy, it actually started the week before my BFP, so basically right on implantation. I then had morning sickness that was worst in the middle of the night, so I would wake up from feeling sick and not be able to get back to sleep. Now at the end of second tri I am still sleeping badly and if I get woken at night by anything, one of my kids, OH snoring, etc, I cannot get back to sleep for an hour or more. So tired!
With my first two pregnancies I slept really well in the first and second tri and only had insomnia right at the end when I was too uncomfortable to sleep.