Fibroid attached to placenta

At my 20 week scan my doc noticed a fibroid attached to the placenta.

Referred me to an oncologist at a bigger hospital , but they won't see me for 4 more weeks to see if the fibroid has grown or shrunk.

They won't tell me anything either, like if I should worry. And I cant find stories about them ON the placenta online.

Has Anyone ever had or known of someone with this? And the outcome?