Green Discharge?

Ive starting trying to conceive in Aug. I was running late on my period and was really glad! i took a test it came out negative to find i started a little over a week late. bummerr. Last night i threw up about 2 am and have been fairly constipated. I also came to find i have green vag. discharge ... not lime..just green...what could this mean?? i wouldnt say " oh its an std" because my partner and i lost it to each other and were highschool sweethearts (: is this an infection of some kind orr someone told me it could be a miscar. but i highly doubt that considering i started...??