Is it too late to start Finasteride?

Hello there - I had a FUT about 5 weeks ago (~2400 grafts) and I’m still going through the thick my recovery (some transplanted hairs still have yet to fall out, etc). I’m concerned because I’m beginning to see balding I wasn’t able to notice before in the crown. It may be due to “shock loss” but is there even a point to starting Finasteride if the areas that I’m most worried about are already losing hair? Will it make a difference if, let’s say, I start tomorrow? Or is it too late? Thanks!