Sadly I got bad thrush right at the end of my pregnancy too....about three times from about 34wks pregnant onwards. The pessaries would clear it up for a few days and then it'd come back.

I had it terrible when I went into labour...I was SO embarassed about it (one of the midwives made a big deal out of it too...nasty woman!) but had plenty of other things to be focussing on.

Just for further advice, I asked my OB after giving birth whether there was something I could take to clear it up post-birth whilst breastfeeding. She told me that the natural bleeding after birth would actually clear it out!