Subchorionic hematoma

Just had my ultrasound today and am 8w 3d but baby measured 8w 0d. I am not concerned about the measurement difference as my cycles are typically a little longer than average. I was diagnosed with a subchorionic hematoma though and that makes me nervous. The doctor didn’t seem too bothered by this, but didn’t really give much information. Has anyone had this before? What was the outcome? I haven’t had any bleeding yet, but I am worried it will start.