Finished 5 day zpack two days ago but can still feel a little pain in my ear and liquid draining to my throat. is it normal to still have few symptoms?

Yes!: Most cold symptoms are caused by viruses which don't respond to antibiotics. In other words, it'll take 7 days to get better w/antibiotics and a week w/o antibiotics. In fact, avg cough lasts 18d in recent study. Check out http://www.drugs.com/mtm/zithromax-z-pak.html. Zithromycin has a long half-life so that it'll last in your system upwards of 7-10d even after finishing just 5d pack.