Oct 21, 2021
Thank you for your very kind comment, and my apologies for the late response. After a brief reading, it seems that the link between the Covid-19 vaccine (mRNA and DNA) and menstrual changes are being taken more seriously now. The National Institute of Child Health and Human Development is funding research on this matter.
https://covid19.nih.gov/news-and-stories/covid-19-vaccines-and-menstrual-cycle
Below is another informative article on this matter if you haven't seen it. It seems that not much is known at present, perhaps for the reasons you mentioned. I'm not sure what to think either at present, but I'll let you know if I'd do in-depth reading and writing on this matter.
