I saw a movie preview I think in the last few months

All I can remember is that someone's consciousness is transferred into someone else's body, who was in a relationship with a woman, but the woman doesn't understand how he has those memories,
It is a thriller/ horror maybe?
I remember seeing blood in the trailer

Any thoughts?

There has got to be a half dozen movies like that... but the only one I remember is Down to Earth (2001) starring Chris Rock.

It would be easier if you explained how the consciousness was transferred. Was it magic? Divine? Ghostly? Technical?

It was in the past few months I saw a preview, so it is a recent movie,
I think it happens in a hospital, but it doesn't happen medically, something about blood touching and some magical/divine way it is transferred, and I feel as if it had a darker theme

In the trailer there was blood running across the floor in the hospital room.

Might be Possession (2009) (http://www.imdb.com/title/tt0368563/)
Here's the trailer: YouTube - Trailer Possession (2009) Sarah Michelle Gellar (http://www.youtube.com/watch?v=_wcv5jgZ8zE)

Sounds like this movie to me. Could be wrong.

Surrogates (2009) - Movie Info - Yahoo! Movies (http://movies.yahoo.com/movie/1810022523/info)

Thank you quinn f!

It's possession for sure!

Lol sorry! :(

You're welcome.