Could The "clear Ball" During Menstruation Have Been An Miscarriage?

I'm 23 years old, 5'6", 180lbs and the only relevant medical history i can think of is 5 years ago i had a child c-section no complications...about three to four months ago, during the beginning of my period i woke up to find a quarter sized clear ball in my pad. I had talked to one of my friends (a nurse) and she suggested it may have been an early miscarriage. I bled for two-three weeks and then everything returned to normal including my cycle. I missed my period this month and just took a pregnancy test and it gave a positive result...i do have a doctors appointment but i was wondering what to expect because now i have many concerns about what happened the earlier months and i wanted an opinion on what might be going on?