What Causes Delayed Periods After A Medical Abortion?

I had a medical abortion on April 7th. 42 days after I had a very light period. It is now 39 days after the last period and I still have not had my period. Should I worry? I am 39 and am worried I may have shocked my system into shutting down. I had problems a few years ago. I was in peri menopause early. It was corrected through the use of bio identicals. Just worried I may have pushed my body back in that direction. Your advice is appreciated.