I am having this vaginal discharge what could it be

Thad my period 2 days ago and start ovulating in 11 days according to my flo app. I had got tested for any stds and got results on March 18 everything came back negative I did have protected and unprotected sex since but just recently began to have this off white, watery discharge on my vaginal walls, when I wipe it does seem a little tint of green.. I have no itching or burning sensation inside my vulva. Should I be worried about stds? or anything else? (will try to include image)