Not yet married but feel married.. Confusing?

Kellie • Mother of three and currently ttc #4 due to health issues my chances are starting to shorten every day! Staying positive and wishing everyone lots of baby dust
Me and my live in partner has been together for almost 6 years.. He hasn't popped the question and I am starting to feel too comfortable with him not popping the question.. We've talked about marriage but we haven't gotten there yet.. Very confusing I know I just don't want anything to change we are in a great place right now.. I don't know how to explain it but I just got this feeling last week that I am too comfortable.. Am I? Shouldn't we be married seeing we've been together for 6 years?