You can drink your pills from the first day of your period or anytime as long as you’re not pregnant. But abstain from sex or use condom for the next 7 days to be perfectly sex. Remember to drink your pills every day, 24 hours interval, or else mawawala yung bisa ng pills if you miss kahit just once. If you did, drink as soon as you remember and again, use condom for the next 2 days. Hope this helps