8 months on Propecia, stronger but still shedding, why?

[TheAnh]

Hi everyone, I am 26 years old and I were in NW4 8 months ago. Therefore, I went to a dermatologist and he prescrbles me Propecia. There are two things:

• First, my hair in the crown is become "stronger" and "bigger in diameter" than before.
• Second, although the diameter of the hair is bigger, but it is still shedding day by day, when I wash my hair, not only in the crown but also all of my head.

Does it means Propecia work? Indeed, the diameter of the hair is bigger for sure. But why It still shedding, without stopping about 4 months.
About side effect, no. My sex drive even increases over 8 months.
Thanks for your help.