Tandem nursing and restless sleeper

I know I have seen a few posts about nursing while pregnant. I still am nursing my 22 month old. She was just nursing before nap and maybe twice at night time. I am nervous because she seems to want it more now and sleeping has been a nightmare lately. I am soooo nervous for the baby to come. I am worried about sleep. Will they both keep me up but at different times? Has anyone tandem nurses? How was it for you? Can anyone else relate to a toddler that has never slept well?