need help with armholes

[mybell]

Hello,
Please help. I always have problems with shaping the armholes. The instruction is as follow: (BO 3 sts at beginning of next 2 rows. Next
row: k1, w2tog, work in pattern to last 2 sts w2tog, k1. work 1 row in pattern.Repeat these 2 rows 5 times more.)

My problem is I would follow the instruction to BO 3 sts at beginning of next 2 rows but my armholes are lop-sided. (one armholes higher then the other). What am I doing wrong?

Thank you,
mybell

[Ingrid]

This is a