seeing my derm in two weeks. start rogaine now?

After looking through this subreddit I've decided that yes, I am in fact losing my hair, and yes, I'm going to take finasteride+rogaine. The good news is that I still have a lot of hair, I think even more than what rawtashk had when he started. I've made an appointment with my dermatologist but he can't see me for another couple weeks. Should I start using rogaine now, or is two more weeks not enough to matter?