Polygons changing shape automatically?

[LGritsavage]

I'm a student using ArcGIS Pro and I'm doing an assignment where I am trying to digitalize an island. I've added a new shapefile, and it matches the projection of the rest of my layers (UTM 2N NAD83). However whenever I draw a polygon around the island, as soon as I click finish, the shape changes into a triangle or rectangle. How do I stop it from automatically becoming a regular shape? (My island is shaped like a round blob with lots of ins and outs)

[DanPatterson]

make sure you are creating polygons and not regular shapes

Create polygon features—ArcGIS Pro | Documentation

There are only so many drawing tools available sounds like you are creating regular shapes

Create squares and rectangles—ArcGIS Pro | Documentation