Does water have iron/iron bacteria

QUESTIONS: Do I have iron bacteria? If there is no iron detected in the water does that mean there cannot be iron bacteria or can it mean that the bacteria has consumed all of the iron?

I used a test kit to run some tests on my well water. There was absolutely no iron detected, but some water I sampled from the bathroom was slightly slimy (indicating presence of iron bacteria I think). However, there was no smell, and when I left a sample of water out for a week, not iron bacteria colonies grew.