I took Microgynon 30 on the first day of my period, about 5 days later I had unprotected sex. Am I safe?

I take the pill every day at around 6 - 9 am. However, one of the days I was on the pill, I was sick around 4/5pm. I am soooooooo worried so could anyone please help me? The sex was with my boyfriend and we both are free of STDs etc.