I have a gardenia plant indoors. It's about a year and a half old.
It started to get yellow leaves so I repotted with fresh potting soil
it into a larger terracotta pot.(I think my husband was overwatering
it). Now the leaves are drooping but are green. i went to take a
look today and noticed several very large round spherical eggs in the
soil!!! I don't think they're soil gnats or anything because each egg
is almost as big as a pencil eraser and whiteish yellow! My husband
popped one with a pen and it was semi hard and filled with liquid. We
don't know what to do and can't figure out what these things are!

I doubt that they are "eggs", potting soil is usually sterile, but rather
something added to the soil such as perlite, to help hold water for the plant.
sed5555