Ok, so there's this other movie......

Ok, I saw a movie once that I thought was this movie, but now I just finished watching this one, and it's not. It's kind of a mystery/thriller, like Carolina Moon. The movie I saw had two women, and in one scene they were in a bathroom, and one came out of the stall crying and said she got her period, and then the other woman said that she figured that was normal for most women. Then the other one said that she and her husband/boyfriend/someone had been trying for a baby. Another scene I remember is near the end, where there's the woman, her husband, and their baby, and another woman is kinda psycho and wants the baby, and chases the woman and her husband around their house trying to kill them, because she thinks that their baby should be hers, and the other woman and her husband either kill her or the cops get her, and they take their baby and leave the house. I'm sorry that my description is so vague, but it's really all I can remember. If anybody knows what movie this is, I'd really appreciate it.