I need sleep lol

my daughter is 11 months. she has always slept good til 2 weeks ago, she doesn't sleep for more then 3 hours at a time now & I'm not sure why or how to get her back on track.. she also now sleeps more during the afternoon to the middle of the night rather then all night, so her days and nights have swapped.. I need any advice I can get please, especially since I'm pregnant with #2, I'd like her sleep to be better before her brother or sister arrives (: