Oval Crochet

On the turn part, from the 4th row on, the pattern of the increase is: 

4th: 2 dc + 1dc
5th: 2 dc + 1dc + 1dc
6th: 2 dc + 1dc + 1dc + 1dc

7th: 2 dc + 1 dc + 1 dc + 1 dc + 1 dc

and so on...