Swirling blood?

Hi all,

I am supposed to be 6w2d today. I had an ultrasound on Thursday, 5w4d, and nothing was present..just thickened lining. Today there was a gestational sac. My doctor really didn’t say anything at all to me. It’s kind of 50/50 at this point. Typically my cycles are 28 days, so I should be 6w2d. But maybe this one time I ovulated way later? I don’t know. But they said they could visualize swirling blood. They didn’t say anything about it just that it’s not good. Has anyone experienced this? I am bleeding. Red blood. A decent amount but no cramping.