If i were you, for 48hours dont eat anything with dairy in it (as it makes the diaherra worse) and drink HEAPS of water.. Water will flush out your system.. if in 48hours the diaherra continues, then i would see your GP... otherwise i really wouldnt worry at all.. i think things like that are very VERY rare, and proberly only happen in the very first couple of weeks of pregnancy..

Take care!!