UserX
I haven't used EFT, however, I recall experiencing yawning, sighing, changes in breathing patterns, and feeling very tired sometimes when I used to practice taiji, qigong and meditation. As I recall, my teacher explained that all these were just manifestations of energy circulating. And it definitely changes over time as healing progresses. If EFT has the same sort of effect, you might also experience yourself breaking smiling more or even breaking out in spontaneous laughter, lol! Anyway, it's nothing to be concerned about; just welcome it as a sign that you are on the mend!