I'm done...I think?

So, to quickly recap my roller coaster of a miscarriage... I had blood work last week showing my HCG levels dropped, and my doctor's office told me a miscarriage was imminent.  They drew blood again just to monitor the drop, only to find my levels had gone up.  They sent me to the ER (I was on vacation out of state) because they were worried about a possible ectopic.  At the ER, I found out that not only was it not ectopic, but it was still a viable, vaginal pregnancy with a heartbeat.  Umm... What?  My doctor made it sound like my miscarriage should be happening at anytime.  Well, my doctor at home was not convinced due to the results of my blood work and was planning on seeing me early next week.  Within two days of the U/S at the ER (which was on Monday), I began spotting, which quickly lead to cramping and heavy bleeding.  I have been bleeding heavily for about two days, and I just passed something that was bigger than a golf ball.  I couldn't bring myself to look too closely, but I'm pretty sure it wasn't a blood clot.  The thing I'm confused about is that it didn't hurt at all to pass it.  In fact, it took me completely by surprised.  Do you think my miscarriage could be done, or is there more to come?  I know that I won't know anything for sure until I go to the doctor next week, but I'm just confused as this didn't jibe with my stories I have read on here.  Also, is it possible to miscarriage that quickly after seeing a heartbeat on Monday?  My doctor made it sound like there was no chance this pregnancy could last, but I was still surprised by the timing.