Can I Continue to Use Tazorac on my Chest and Boobs Before my BA Surgery in a Month? Can I Have Any Complications by Doing This?

I think I would stop using it in the areas of the incisions.  Also, unless you are using huge imlants, you should be fine to use it on the rest of the breasts- particularly the decolette, which is probably where the blackheads are bad anyway.

If it has improved your skin I see no reason to stop its use. Many surgeons have patients on Retin A, a related medication to prep the skin for facial surgery. All the best. 

Just to be on the save side I would discontinue the use of Tazorac for two weeks prior to surgery an for two weeks after surgery.  If there is any question ask your plastic surgeon directly.