Bleeding

Posting on behalf of my sister. She’s 6+4 weeks pregnant. She went to hospital couple of days ago due to pain and bleeding (but only when she wipes). She had a scan today and everything was good, baby looked good, good heartbeat and was told they don’t know what could be causing the blood. My sister is nervous and feels something is wrong although scan shows others wise but it’s understandable. Did anybody else have this and what was the outcome? She doesn’t get a scan now until her routine one at 12 weeks