Diarrhea!!

I'm taking metformin 1000 mg for pcos. It's been a week. And I already have experienced diarrhea. Has anyone of you experienced the same? And I have also lost 2 kg or 4.4 pounds by now!! But is it common or ok to have diarrhea? It's not like I have to stay near bathroom. It comes suddenly and then again everything is  fine. Anyone experiencing the same thing?