Your ultrasound and
AMH report back up what your gynaecologist told you. The AMH is below 0.1, and the scan's own impression reads poor ovarian reserve with a thin lining, both pointing toward perimenopause rather than a pause caused by your recent illness. A severe infection can delay periods for a few months, but it rarely pushes AMH this low on its own.
Next Steps
It's reasonable to continue the watch and wait plan your gynaecologist suggested, and ask her about checking
FSH,
LH and estradiol to see exactly where you are in this transition.
Health Tips
If your periods don't return over the next few months, please discuss it with your gynaecologist again, since bone and heart health need more attention once periods stop for good.