Married to soon?

So this is kind of a weird question. My fiancé and I have been together 5 years I love him a ton don’t get me wrong but we’ve only been with each other and I didn’t go to college so I constantly think about how different things could be when o turn 21 next month. Going out. Meeting people experimenting, I want to marry him but I also feel like I’m missing a whole part of growing up.

*im not thinking I’m going to find something better. I mean we’ve been together for awhile and I love him more than anything. I just wonder if what I’m missing is even worth it. Am I really missing anything by not sleeping around? I can still party and what not but with him and not random hook ups.