Upright hair or miniaturization? 18 year old male. Dermatologist said I am forming a mature hairline.

Dad, and both grandfathers have mature hairlines 1 of 4 maternal uncle has MBP, started in late 20’s Other 3 uncles have mature hairlines. My hairline changed in May, with a huge shed. I visited a dermatologist, and he said I am forming a mature hairline, and normally a shed is not a sign of MBP, more likely TE. The shed stopped 4 weeks ago, but now I shed some small hairs in the shower, I am confused to weather they are miniaturized or upright hairs, they are shedding from all over scalp.