27wks pregnant and cant sleep?

Hi guys xcan any one relate or help me with this dilema that i am having at the moment, im going to bed in the night around 11 and i am rather tired but lately it is taking me ages to acctually fall asleep and when i do finally get to sleep im up every half hour - 20 mins tossing and turning and constantly awake i haft to then get up for work at witch time i am really really tired can any one help me b coz it is affecting my social life and my love life thanks guys xxx