I too found the same result when I just took Rogaine; however, it eventually did stop. I never did notice good results on just Rogaine. Therefore after about 8 months, I went to Propecia and within a few days I did not lose a single hair (Or at least it seemed that way, I am sure I lost some). My mistake was that I then stopped using Rogaine because I thought Propecia would do the trick (plus Rogaine made my head flake.) I started to lose a lot of hair (may also be because I have been more stressed). The end result - I am now on both Rogaine & Propecia.
Not sure how it is working