With the pessary and internal creams it's usually the applicator they have issues with (as this is adding an unnessecery, foreign object to your vagina). If you can get it in there with your fingers they're usually happier.
The tablet is a definite no-no unless prescribed by a consultant. I had an 8wk patch of thrush late 1st and into 2nd trimester and 3 rounds of pessary and external creme did it.
Remember, if you're in the UK you get you MATEX card and will get all this stuff free if you visit a prescribing MW/GP/hospital.
Also, if you do use the pessary it's TOTALLY NORMAL to have a rush of fluid usually the morning after you've inserted the pessary (mine was enough to soak my pants, and trouser-crotch), mine was accompanies by some white chalkish stuff. But, if worried, always get any fluid-rush checked.
It might be worth making a drs appt as when I had it, they took swabs to check it def. was thrush and not a bacterial infection/whatever...
Meanwhile eating (and applying externally only if it takes your fancy) natural, unflavoured yogs, only using gynea tested body washes (like femfresh) and no deoderising products, drinking plenty of water, wearing cotton pants, hot-washing your pants in non-bio (don'tuse fabric conditioner either), ironing the gussets (if you have the patience) and going comando or at least avoiding clingy stuff in that reigon, when you can, will all help.