Period stopped after taking contraceptive pill?

Hi, I've had problems with previous contraceptive pills including Microgynon and Celest, as they both made me very ill. My doctor decided to try me on the Yasmin combined pill. As you must know, you're meant to take it on the first day of your period to be instantly protected, however I started it on my second day. I took it in the morning, however by lunch time, my flow had stopped and the tampon was completely clear. I've continued taking it and its been about 5 days and still no period. I'm quite concerned as this has never happened with any other pill I've taken. What could be causing it? Is this normal? Thank you!