Umbilical cord Complications

I’m currently 34 weeks and 4 days, and today i had a visit at my OB. I was informed that the flow of blood in the umbilical cord was “moving slow” or not flowing the way it should be. All i was told is that I have to come back in 4 days and they have to keep an eye out on me. The doctor acted like she didn’t wanna say much to worry me, but I did ask if worst comes to worst what would happen and she said I would deliver early. Has anyone heard or been through this? I’m worried and confused and I need more information on what the hell is going on 😓😥