I'm 18.

I'm 18 and live with my mom. I have good grades, never gotten into seious trouble, have been dating the same guy for 10 months.. and my curfew is still 930 pm on the weekdays and on the weekend it's midnight. I've never went against her rules or snuck out. So why won't she let me spend the night at my boyfriends house? Is she too strict? What can I do to change her mind? I love her and don't want to go against her wishes..