If menstruation occurred around 3 p.m. and I took my first Vines tablet the next day around noon, am I already protected from pregnancy?

Good morning, recently I started using vines tablets, previously I used only condoms hence my question. I got the period on Friday at about 15 o'clock and took the first tablet from the first pack on Saturday at 12 o'clock because I had no access to them before. My question is am I protected from pregnancy? Has this delay had a big impact and should I use an additional contraceptive for a month?