Hi I Got My Period Yesterday And It Seemed Just

Hi I got my period yesterday and it seemed just lighter than normal but it was only the start. Well now I tried to use the bathroom and before I sat down I had almost like a pink/ clear water rush out of me it was about aquarter of a cup worth. I have no real pain and my period is normally a week or two late this time it was a day late. I'm 21 and had a baby 3 years ago. I do have a partner and have unsafe sex but it's only been like twice this last month and would of been before I ovulated. My health has always been fine I get check ups the worst is a cold twice a year.