Uy momsh, that's actually something you should ask your OB about kasi ang bawat katawan different talaga, yung iba 2-3 days lang, yung iba 5-7 days, depende sa pill at sa body mo rin! A few of my mum friends nag-adjust din ng pills dahil ang period nila naging too light or too short, and ang doc nila na-regulate ulit. Hindi ito unusual, pero important na i-clarify with your doctor kung normal lang ba ito for your body or kailangan ng adjustment, lalo na first time mo pa lang with pills, so better safe na!