unprotected sex on first day of period

Hi Mommies! Malaki ba chance na mabuntis kapag unprotected sa first day on period? *Actually while doing it tsaka lang lumabas period ko. 3months na kasi akong delayed (irregular lang, hindi dahil buntis) Nagwoworry lang ako dahil napapadalas yung ihi ko, antukin at laging pagod.