First thing in the morning, before you put ANYTHING in your mouth,
get a clear glass of water. Better still; leave it by your bed the
night before. Work up a bit of saliva, and then spit it into the
glass of water.
Check the water every 15 minutes or so for up to one hour.
If you have a candida/ yeast infection, you will see strings
(like legs) traveling down into the water from the saliva floating
on the top, and "cloudy" saliva will sink to the bottom of the glass,
or cloudy specks will seem to be suspended in the water.

If nothing develops in 30 minutes and the water is clear except for
the saliva on top, you're probably Candida/ yeast free.

 One other way to confirm if you have Candida is to eat two cups of
kefir (original version). If you get abdominal cramps and/ or
rumbling in your stomach/ belly you most likely have a strong yeast
infection.

Oil of oregano together with Kefir has proven to be very effective
against Yeast infection.

You can read more about it on http://www.pieternel.com

In any case you might have to start with one ounce of Kefir every
other day and advance slowly if you want to use Oil of oregano
together with Kefir to diminish the yeast infection.