Should i allow my 3 wk old baby sleep alone in his cot and in his own room? Or should a caregiver sleep with him in the same room?

All my babies sleep in their own room, in a cot since newborn. What I do is install a baby monitor in the room so I can hear their cries. At the same time, I put a mattress next to them in case they are inconsolable and I need to spend a little more time with them in the baby room.