*UPDATE* anatomy scan at 23 weeks have to come back for another

Nichole
I just had my anatomy scan and I'm 23 weeks. When I was leaving the ultrasound tech said that they are scheduling me for another ultrasound at my next appointment in four weeks something to do with the placenta. Has anyone else had this and if so what were they looking for?  The ultrasound tech couldn't tell me anything and I have a message into my midwife but until then I'm just wondering.
UPDATE: m midwife just called to explain. She said I have a second "satellite placenta" in addition to the main placenta and that the second ultrasound will be baginal and they just need to check that the blood vessels going from the satellite placenta to the main placenta aren't covering my cervix. If there aren't then I can deliver normally, but if there are I will have to deliver c-section. So all in all good news in regards to baby and her health!