What are the signs to look out for regarding hair loss on cycle?

I'm 3 weeks into my first cycle (500mg test c), and my scalp has been pretty itchy the past few days. No idea if this is just because my body temperature has gone up significantly since starting, or it's an early sign of hair loss. For those of you who have had experience with hair loss on PEDs, are there any specific signs? Or countermeasures? Do I not take the risk and go get a finasteride prescription?