Last period short 3 days ( usually 5-6 days),then spotting ( discharge with blood) since day 5 till day 9 then stopped, again start day 11

Irreg. bleeding?: Not sure what is meant by "again start day 11?", but if you mean your bleeding started again on day 11, I would get a serum HGC pregnancy test. If positive, see your healthcare provider to make sure you do not have a tubal pregnancy. If negative, the bleeding may just be not ovulatory, which is frequently irregular as you describe. You need to be examined for a more certain explanation.