Can't get expected readings using PulseIn command

Why in the World would they need to ?

Just use the pin designations silkscreened on the board.

Want to use the pin marked A3 as an input ?

pinMode(A3, INPUT_PULLUP);

Want to iterate through the pins marked A0 to A5 ?

for (int p = A0; p <= A5; p++)
{
  digitalWrite(p, HIGH);
  delay(1000);
  digitalWrite(p, LOW);
}

and so on