I've been trying to see how many children lines i have since
yesterday ....
can i just etch four lines onto my palms with a pen knife ? ...

there could only be 2 possibilities.
1, You are impotent? 
2. You don't how to see. 
if 1 is the answer, never fear, seek advice from the massuer
from Thailand, but it is lightly it is 2. 