6 month old wakes up screaming

Ok, here is our routine. Bath, bottle, bed. She falls asleep while eating I'll put her in her bed and then she will sleep for a good 30 minutes and then she wakes up screaming, not crying. I mean automatically to where she looses her breath every single day around the same time. I have her a doctors appointment Friday. But my mind is racing until them. Any body have any ideas. Also I noticed that she has been jerking in her sleep. And seizures run in the family. I just don't want to think that it's that.