I've been using the yasmin pill on and off for a year, I stopped in August 2008, and wanted to start it again in feb, I got my period on the 10th of feb and should have started the pill then, but I waited till the 19th to take it, I've been taking it now for almost 2 weeks, would I be able to use it as a contraceptive?

Better safe than sorry, use a condom until you've been on the pill for one month straight with no issues.

In fact, please continue to use condoms after the birth control takes effect.