Another possibility is having him sleep next to your bed, maybe on a pallet or his own pallet, or even in a corner in your room. (I realize you're probably trying to get him out of your room, but it can help.) Maybe even just outside your room near the door would make a difference.
We have 4, and for the 1st, we had to get him out of my bed when I was pregnant with #2, but anywhere else just didn't settle well with either one of us (Mom or baby) he was 2, nearing 3 then. So, we put him on a mattress on the floor next to Mama. After the baby came, he was still in the room, but not so close to the bed. He was 3. Within a few months, we moved him to his own room. We were still breastfeeding, so I would feed him there in his own room before going to bed, and everything worked out fine. #2 was also a boy, so when his turn came to remove him from Mama's bed to make room for #3, we moved him right into his own bed in brother's room, and he was happy with that (he was 2 nearing 3). #3 was a girl. When it was time for her to make room for #4, she went on the floor next to Mama's bed. After the baby was born, she (2) went just outside the door (not in the walkway) of Mama's room, and that (at 3 1/2) is still her sleeping space. (#4 is 1 and not yet having to make way, but the plan is for him to go in with his brothers when the time comes.)
Good luck!