New and Confused!

[MrsMLJ]

I am knitting a basic dishcloth. I cast on 4 stitches ~ knit that row and then each time I add a stich until I get to 50. Then I drop a stitch and knit that row until I get to 4 stitches and then I cast off. But somehow my square dishcloth isn't square. The end of my dishcloth looks like it has too many stitches.

I am new to knitting so if anybody can give me some advice I would so appreciate it!

Thanking you in advance,

MrsMJ