my son was head down and I was dilated from 28 weeks and his head is normal shaped I also had a very very quick labor and delivery

I don't think you should worry. I believe what actually causes the cone shape is the pressure from passing through the birth canal, and if mama had to push for a long time then it can be more pronounced.

you've been dilated for that long?! thats crazy.

My baby had a cone head, but I didn't notice it and I thought he was the most beautiful thing. Looking at pictures it's noticeable though. It went away quickly. I'm not sure if it's because he was head down so long or because I pushed for four hours before he finally came out

no probably not, shed have to be engaged for that to happen