I think you'll be fine so long as you have a lot of communication so both of you can meet one another desires. (Like if something hurts or doesn't feel good, if something feels good...)

I don't think you should FEEL you need to lose your "vaginal virginity" after you're married, but I do think that you should get to know one another on a physical level and open the door. Maybe if you're comfortable with him seeing you topless, the next time it won't be so bad and you'll go further...etc. Rushing can be traumatic if you're not relaxed.