Baby sleeping with a blanket??

We were supposed to put the baby in his crib tonight. He's 4 months old. But for the first time last night, he kept pulling his blanket over his face. He's never done this before. He's doing it intentionally. I tuck the blanket under his arms and his grabbing it and pulling it up and over his face, then putting his hands back down to his side with them still out of the blanket. Or he will hold it there. It's a crocheted blanket with lots of holes and he can breathe through it, but still it freaks me out. He's always slept with a blanket, so when I took it away, he'd start to fuss. So then I give it back and he pulls it over his face. So now I'm too nervous to put him in his crib but he's really outgrown his cosleeper. What do I do? He hates being swaddled. He just likes blankets. Even during the day, he holds into them.