Talk to Gynecologist on Vaginal Infection

I'm 37+ weeks and was having vomiting, headache and lower back pain(unlike labour one)+ yellowish discharge so went to Er. There the doc did ps and found out that I'm having severe vaginal infection and gave me cyclogest pessary through rectum area but now when I read about it cyclogest is not recommended in last weeks also she wants me to have it for few days also. kindly guide me as it is safe to take them and also through rectum area as I'm unable to take it vaginally.

P.S I'm having planned csec next week so she prescribed me two doses of dexa as well with 12 hours gap.