Poor bloke. He can't get anything right!
If he doesn't propose then you'll feel upset because you really want to get married.
If he does propose then you're upset because you feel he's doing it for the wrong reasons!
Most men don't give a crap about weddings, I think it's a girly thing. It's us who puts all our emotions into it, they hate it! My dh didn't enjoy our wedding day much, he hated being the centre of attention, he hated the suit, he hated the formality. But he did it all for me which I am grateful for!
He doesn't wear a ring either, but that's because he broke it whilst operating his digger.
Methinks you analyse too much.
He proposed. It doesn't matter how it happened or where it happened, it was obviously a hard thing for him to do.
As you said, you've made the commitment of having a child together. He obviously wants to stay with you and make it work. So accept his proposal and live forever after! If you want to that is!