Hey guys. Ive pcos. Get my periods regularly ie every month. My discharge color chAnged last month on 19th december but the actual period flow started on the 21st of december. Me and my husband have been trying to conceive since the past two months. Now ive been nauseatic since the past one week and i didnt get my period yet. I also did the pregnancy test in the morning but it was negative. What could be the possible cause of this delay?