Eh, delay 3 hari after finishing Regulon pills mmang boleh jadi normal lah, especially kalau body mu masih adjust balik, few of my mum friends experienced the same thing and their period came within a week or two. But kalau dah lambat lebih dari seminggu or ada other symptoms yang worry you, better check with your doctor or gynae aje, just to be sure everything okay. Hormones tu kadang suka main-main especially kalau baru tukar contraception! Semoga cepat datang okay