The dot is the smallest mark there is, so it is read as a point of origin, a seed or a single focus. A lone dot in a dream suggests attention narrowing to one detail that matters.
Where in your waking life have you met something like this lately?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.