Could Clotrimazole Prescribed For Vaginal Thrush Cause Overdose?

I am a type 1 diabetic and I suffer quite regularly from vaginal thrush. I was prescribed with a 500mg clotrimazole pessary and double strength cream which seemed to do the trick, but it came back after a few weeks... I bought the same pessary from my local pharmacy and used it but I dont think it worked properly so I bought another and used it, after only 3 days. I know this probably wasn t the right thing to do, but I just want to get rid of the thrush as it s affecting my sex life and becoming a real problem. What I want to know is, is this likely to cause an overdose?