D.K.
You may actually be waking him up. My son was in a crib in my room until 5 mos, mainly so he wouldn't wake his sister since they have to share a room. I didn't realize that I stirred about this time and he would wake up and it was so hard getting him back to sleep, he would have to lay on my stomach to go back to sleep. Since like you I wanted sleep I just let him fall back asleep on me then put him back in his crib. I knew I had to move him out of my room, I would just ignore the fussiness the best I could, which stinks, then I put him in his own room at almost 5 mos and he slept great. If he did fuss he would go back to sleep himself if I ignored him. I knew he wasn't hungry as aroun 2am he woke up for feedings too. I think when you are in the same room with them they sense your every move, sound, if you snored, whatever and once they wake up they just want you. The stages of sleep are they are more in a light sleep at that time too so more sensitive to noise. At least that was the case in our situation. If he is just fussying, try to ignore him as best as you can, if putting him in your bed helps you and he go back to sleep for an hour or so, I honestly don't think it is a huge thing. Just break that habit before you put him in his own room. Get him used to sleeping with noise, the vacuum, phone and so on, I had both of mine nap in a pack and play in the living room until 5 or 6 months to get used to noise.