I have noticed a change in vaginal discharge. it is now light green and slimy but odourless. no itching or pain.

See doctor or clinic: Any new or abnormal vaginal discharge should be professionally evaluated. Typical vaginal yeast (thrush) often can be safely treated with an over-the-counter product, but this isn't typical for yeast. If sexually active and at risk for STD, chlamydia or gonorrhea are considerations. Beyond that, really no way to judge; see your GP or perhaps your nearest NHS GUM clinic. Good luck!