You are correct, it is still your turn (inning), in this scenario.
In the game of 8 ball pool, as long as your called your object ball and it's intended pocket, and committed no other foul, then your inning continues.
Any object balls pocketed incidentally (with the exception of the 8 ball) remain pocketed.
This assumes that it's not the break shot, nor an "open table" situation, and that the "incidentally pocketed ball" isn't the 8 ball.
Here are the World Pool-Billiard association rules that apply (emphasized for clarity).
8 Ball is a "call shot" game, thus, WPA rules for 8 ball reference definition 1.6 Standard Call Shot. This section tells us several things:
- The player only needs to call one of their object balls and it's intended target pocket.
- Extra detail, such as "other balls contacted or pocketed are irrelevant".
1.6 Standard Call Shot
In games in which the shooter is required to call shots, the intended ball and pocket must be indicated for each shot if they are not obvious. Details of the shot, such as cushions struck or other balls contacted or pocketed are irrelevant. Only one ball may be called on each shot.
Section 3.7, Spotting Balls, tells us that incidentally pocketed object balls are never spotted back on the table.
3.7 Spotting Balls (8 Ball)
If the eight ball is pocketed or driven off the table on the break, it will be spotted or the balls will be re-racked. (See 3.3 Break Shot and 1.4 Spotting Balls.) No other object ball is ever spotted.