Why is my discharge green/gray

I began what I thought was spotting last night, my period ended on the 17th, I have never spotted in between periods so I thought it was odd and it has continued since. Then I woke with a mild burning in my vagina this morning and I blew it off. It lasted all day and then tonight when I was messing around I saw this green/gray discharge and I am slightly worried now. Last night it was the regular color. I do not go to an OBGYN and I don’t really want to talk to my mother about this. Any ideas? Sorry about the pic.