Pattern Help!

I am knitting a sweater and I am confused with wording for the sleeves. I am knitting the 3rd size.

The pattern states: Starting with a knit row, work in St st, shaping sides by increasing 1 st at each end of 3rd and every foll
4th (4th: 4th: 4th: alt) row until there are 87 (95: 103: 103: 67) sts.

Does this mean I should increase on every 3rd and 4th row? and after the 4th row should my next row be considered the 1st row again?

Thank you for your help!

You are supposed to increase at each end of the 3rd row and then start counting again and increase on the 4th row the next time and every time after that until you have 103 stitches.

So you count from where it says "starting with a knit row, count that row as 1. The purl row will be 2 and then on the next row, which is row 3, inc at each end. Then the next is a purl and it is row 1, knit is row 2, purl is row 3 and row 4 will be the increase row. It will be another knit row.