Knitting in round, lost stitches - what now?

After completing my first garter-stitch scarf, I’m now trying to move on to bigger and better things – a baby hat. It calls for casting-on 72 stitches, which I’m pretty sure I did. Now about 10 rows into it I only count 70 stitches. I’ve gone over what I have several times with a fine-toothed comb and can’t find any imperfections. Can I keep going, or will this mess things up when it comes time to reduce for the crown? Here’s the link to the pattern:

Thanks much,

I think you’re fine continuing with the 70 sts you have. It shouldn’t affect the size too much. On the first decrease row it calls for k6, k2tog around. With 72 sts, you would do this 9 times in a round. When you get there, substitute k5, k2tog for two of those 9 repeats and you’ll be right back on track with the pattern. Cute pattern, good luck!

Or, you could increase 2 stitches on a round - one at the beginning of the round and one at the mid-point. Then you’d be back to 72 stitches and proceed as directed.

Good luck!