Apologies if you're already learnt this but I was unaware until recently (as were several of my friends)...
I'm 48 and in the depths of the raging perimenopause. My GP has become familiar with me visiting to discuss my array of bizarre and uncomfortable symptoms! Following a Mirena fitting last year, I was in constant discomfort and felt like I had never-ending thrush/BV. However, I treated for these and had swabs which were clear.
Rather than being linked to the Mirena, it transpires that I've simply become more sensitive to chemicals e.g. soap and shower gel. GP advised me to only wash my bits with water and although initially sceptical it's been a revelation. No more itchiness. She advised against "feminine washes" too. Just though I'd share in case it helped anyone :).