The $Q(total)$, would be the same $Q$ as in the monopole term.
For the dipole term, you took $Q$, copied it, charge conjugated the copy, and placed the charges a $d$ distance apart. The net charge of the dipole was $0$.
Let $(Q,-Q)$ denote the dipole.
For the quadrupole, you took the dipole, copied it, charged conjugated the copy - which gave you 2 dipoles, namely, $(Q,-Q)$ and $(-Q,Q)$.
Then the 2 dipoles were joined together at the $-Q$ charges on a straight line so the quadrupole looked liked this: $(Q,-2Q,Q)$.
The length of quadrapole was $2d$. The net charge of the quadrupole was $0$.
In short, the dipole and quadrupole terms measure the charge distribution of the charge $Q$ in the event the charge distribution wasn't a pure monopole.