Are either of you working? Have you left the family home? Have you started to save for a downpayment on a home? Are you finished school?
Unless or until you've done at least two of those things, I suggest you relax and enjoy your relationship and worry about the next step up in it once you've accomplished one of those life-steps first.
Take if from someone who married their high-school sweetheart. He said he never wanted to get married too and here we are.. over 30 years later still enjoying one another having married, bought a couple of homes, had a daughter and enjoyed seeing her get married and buy her own home this year.
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion