[BBV]

So I just had a miscarriage at home and I believe I was about 4 months along... Well right afterwards I went to the ER because of the severe cramping and bleeding and they discharged me saying they think it was signs of a threatened miscarriage and that I could still be pregnant... After they had already said something like how they could only test how far long I was up to 3 months, I believe, and they told me I was farther along than that. And I know what I saw and went through was a miscarriage... And after I got home I realized that I have had an early miscarriage before, without knowing it at the time. Well anyway about an hour after having the miscarriage I started getting this sharp pain in my side, like my ribs or something and its just getting worst. It almost feels as though I pulled something or something is jabbing into me and the pain takes my breath away... Could anyone tell me what might of been/could be the cause for this? And also if its possible that I was carrying twins but only lost one?