Is it okay for me to let my 6 week old put himself to sleep?

I have a 6 week old baby. We’ve been putting him to bed at the same time every night just to try to establish a bedtime routine. We do bath time, a baby massage, and then I nurse him to sleep. Tonight he was really tired and drowsy when I put him in his bassinet, but it’s been about 45 minutes and he’s still awake. He’s not fussing or crying, he’s just relaxed and laying there. Is it okay for him to fall asleep on his own like that? If he gets fussy or upset I will definitely go get him, but as long as he’s content is that okay?