Depends on what's in the "regular shock packages".

You've got a problem, however. If you fully dissolved the 3# of stabilizer, you should now have a CYA level around 40 ppm. If you use much trichlor, your level will continue to climb.

I'd recommend using plain 6% household bleach to shock - that will not add CYA. A 96oz jug of 6% bleach will add about 5 ppm of chlorine to your pool.