big finasteride shed-cycles?

are sheds normal with fin? im only using minox on my receding area not my crown so i think its the fin.what are the shed cycles? ive been on fin for about 15 months and this is probably the biggest. i thought that once you tolerate fin the sheds ease off? i do know that shedding is normal in the cycle but at the moment mine is abnormal. the last time i lost this much was 8 months ago so i thought because the fin is working(hairloss stopped) it wouldnt revert to that again.

anyone at all?