Infant having nightmares?

Rachelle

My 9 week old has started crying in her sleep. It happens very suddenly and she goes from being completely quiet to screaming like she’s scared. The only way I can get her to stop crying is to pick her up, but she doesn’t ever seem to be awake during all of this. The first time it happened was 3 nights ago and it has happened multiple times each night since, usually later at night but tonight it started less than one hour after we put her down for the night. Has anyone else experienced this? I tried to research nightmares in infants and I’m finding conflicting information, most sites say they don’t begin until 2 years.