In Enemy, when teacher Jake goes to agency the security guy says he (thinking he is the actor Jake) hasn't set foot in agency in 6 months.
Then, wife of the Actor Jake meets teacher Jake. When teacher Jake asks she says she is 6 months pregnant.
Is there some sort of hint here meaning the actor Jake personality is losing his grip since the pregnancy of his wife.
Ok I'm gonna go out on a limb here. I found a very interesting plot explanation here that I really think you should read. For the sake of brevity however, I'm going to only pull out the essentials to answer your question.
1 - The movie is not shown in chronological order
The author of the article claims that the movie is shown in a different order than how events actually occurred and that the first event is the car crash. This car crash occurs 6 months before all the other events of the movie and is the cause of
2 - Helen is not 6 months pregnant
When Helen meets up with Adam she tells him she is 6 months pregnant but this is only a reference to the fact that Anthony was in the car crash 6 months ago
I need to add that this is my own interpretation. She meets up with Anthony who is currently in the mindset of Adam and asks her how far along she is. It is possible that she really is 6 months pregnant but let me explain why I don't think she is...
3 - Helen realizes Anthony is actually Adam when he visits her at the end
Helen knows her husband is not doing well psychologically. She has discovered he has a split identity as Adam. When Adam visits her at the end, when supposedly Anthony is on holiday with Mary, he asks her if she needs anything
He says that he might think she needed something after being in the pool and you know because she’s 6 months pregnant, and here at this point the light goes on in Helen’s head and she starts to realize the husband is being different again, so she is going to put it on a test by saying “Come to bed”.
And there you have it. I think that she only told him she was 6 months pregnant when she met him for the first time as Adam, which is why she was tipped off to him later after he mentioned her being 6 months pregnant. I could be wrong, in which case the fact that she is 6 months pregnant is indeed either a coincidence or simply a convenient clue to point to the truth about the chronology of events.
To add to the answers here:
1) Helen is 6 months pregnant. When she meets the Adam personality. She is shocked and she simply answers the question about "how far along". She's actually 6 months pregnant. Other visuals of her confirm this too.
2) When the Adam personality goes to the talent agency, the security guard only speculates that it's been about 6 months. So it could be about 5.5 or 5 months also.
This only means that Anthony gave up on his acting career soon as Helen conceived. He took up another job that gave a consistent income.
Adam’s personality is doing the right thing by taking up a profession which is consistent with the upcoming responsibilities of a baby.
However, Anthony is not able to deal with that pressure of not being the flamboyant person he wants to be. Hence he creates Adam who is a boring guy. In summary, it's not exactly 6 months but the pregnancy and the alternate personalities are very much related.
