Confused and Impatient

So I had my first miscarriage on July 12th with my period returning 5 weeks later. On September 11th I found out I was pregnant again only to find out it was a blighted ovum. I passed everything on September 30th and my HCG was back to 0 by October 15th. I still haven’t had a period.

My husband and I haven’t been trying but haven’t been preventing. On December 5th I had some very light spotting in the morning but nothing more the rest of the day or the next day. On December 7th I had a little spotting when I wiped once and that was it. I’ve never spotted before a period in my life. I haven’t had cramps or anything. I talked to my OB on December 3rd about not starting yet and she said to give it a few more weeks. I’m just confused as to what this could be? Implantation bleeding or my period? How long should I wait before I test if I don’t start my period?