Should I be worried?

[Superfantastich]

If you take it on that day, yes it does (did for me anyway)

[Lite]

So I finally have BC pills. I went to see my doctor earlier this month about it. She told me to start the pill the first day of my period this month, which was yesterday. She said it'd take 2 weeks to work. It really kicks in that fast?

The first 2 weeks after your period are when you are most likely to ovulate. After that time the risk has declined and your hormones are not being regulated by the medication. Only, they don't tell you this because then some idiots will think they only need to take 2 weeks worth of pills each month...At least, that's how it was explained to me. Thus the 2 weeks.