I would like to say ask if the pregnancy
was confirmed by-
1. A doctor's examination of the clot you passed, preferably by histopathological examination.
2. A blood pregnancy test. OR
3. An ultrasound
that clearly showed a pregnancy in the uterus
If any of the above was positive, then yes, you did have a miscarriage
and it is best to go back to the doctor to see why you are still bleeding. The cause can only be ascertained by a clinical examination and blood tests and an ultrasound scan.
However, if none of the above was done, the possibility of pregnancy in the first place itself is questionable and you may just be having irregular periods
In any case, go and see your doctor and hopefully you will find an answer.
The possibility of twins and miscarriage of one twin can is there, but till you see your doctor and have a scan, these are all merely speculations.