Hard to say. Your mind could of been acting out a fantasy but it didn't complete because whatever woke you. It could of been trying to show you how he manipulates you to get back in, but it's your son who will also suffer and grow to hate him or you or both.
Regarding the possibility of your son waking you subconsciously, it could of happened, but unless it's an incredibly strong bond or he is very spiritual at his age I doubt it [or he was going to the bathroom and the sound alerted you] I've had a similar experience, I was having a dream where I was a ghost in my grandmother's house and I followed her into her bedroom where she stopped breathing so I hugged her until she yelled at me she would be sick and she ran out of the room to the bathroom and I awoke. It was 1:47 am. A few days later I was speaking with her and I mentioned I had a dream about her, she replied 'you too? I had one two nights ago, you came into my room and hugged me so tight I told you I would puke if you didn't let me go. I woke up and ran to the bathroom and threw up.' I asked her what time and it was 1:47 am the same day. So I believe it's in the realm of possibility your son entered your dream, but due to his age I doubt he would have the spiritual strength. More likely he sensed your pain as a result of some close bond. But, you never know, take a leap of faith.