2 year old toddler coming into bed at night

[cyphercat]

Our dd has slept very well from when she was about 1 year old on her own cot in her bedroom. About a month ago, she has started to come into my bed around 3am at night and I have let her as I do love listening to her sleep and knowing she's warm in bed with us....(and pluspoint being that she does wake up MUCH MUCH later which is around 8am rather than 7am..) However I'm 30 weeks pregnant and will need her to sleep in her room again...
I know it's my fault that I didn't put her back into her bed when she started coming in.. Anybody know a gentle way to lure her back to her bed at night..?? My DH is convinced that she won't go back now she knows how comfy our bed is.