I've been bleeding for 3 weeks and 1 day with microgynon 30 my doctor changed me to yaz (drospirenone and ethinyl estradiol) 5 days ago and the bleeding still isn't stopping?

It's OK: Well, first of all bleeding all the time isn't just inconvenient, it's downright annoying! Changing birth control may work but you will need to give it 3 months or so to kick in. I strongly advise you keep taking the pill as directed. You may bleed irregularly over the next month while your body adjusts to the new hormones. If your bleeding hasn't improved by the third pack, see your gyno.