Yarn over then purl stitch

The pattern I am doing at the moment has this in the row: K2tog, yarn over, purl.
The wool is already at the front of the work in preparation for the purl stitch so does this mean that I need to wind the wool twice around the needle before I do the purl stitch? If I don’t I believe I will end up one stitch short on each row.
Thanks in advance for any help.

Yep, you have to bring the yarn to front, over the needle then to the front again. There’s only one loop on the needle though.

I can continue knitting now…