Is it possible I had a very early on miscarriage?

Yeah it was most likely a miscarriage and the good news is it completely expelled itself on its own. Sometimes pieces are left behind and you need surgery or risk infection. About 50% of conception ends in miscarriage but only 30% of conceptions are diagnosed pregnancies that end in miscarriage. 20% of conceptions end in miscarriage and the mother never knows she was pregnant. It just looks like a late extra heavy, extra crampy period. The intense pain usually subsides after the actual fetal tissue and placental tissue pass. I am sorry for your loss. If you are trying to have a baby wait at least one normal menstrual period before you try again. Odds are your next period will be perfectly healthy.