I was on yaz for 4 months. i had spotting that didn't stop despite skipping the placebo pills each month. i experienced 1 week of withdrawal bleeding. its been 2 weeks since it stopped and i just got my period. will this period be shorter than normal?

The bleeding described is not a "normal period", which is defined as that coming after an ovulatory cycle. The most common cause for bleeding when on low dose BCP's is b/c of non-punctual taking of the active pills. Take the active pill within the hour of the prior day's pill. If bleeding occurs, stop the bcp's, wait seven days, and start a new pack, keeping punctuality a premium.