Need help bad? Scared😢

My sister is 24 weeks along and she starting bleeding pretty bad like a period. She had went to the doctor and they gave her a pap and they told her that the blood was not coming from the baby? So where? They have a appointment again Monday and she still bleeding bad? They also said it was to early to take the baby. She has high BP problems lately and the baby was totally healthy. Anyone else have this problem or knew anyone who did, and what did the doctor do?