Thanks for the input, dear friends! After looking at the pattern again, I've decided that it really doesn't matter where I start round 10. The number of motifs in this round doesn't match the large motifs in the earlier round, so I can't see that it makes any difference where round 10 begins.
I kind of like that I will have to rounds finished when I've completed these motifs, but something looked off.
Oops! I joined the first ring of round 11 in the wrong place! I'm not going to fix it now. I'm going to work on the next round 10 & 11 motif so that I can see how it looks. I may even work all the way around before fixing this.
I wonder if my brain is just weary from all the end of the year activities at school? It seems like a good excuse to me!