You had dark looking clots and something that looked like a piece of skin could this be a miscarriage?
This isn't a matter for speculation. Call your doctor.
If you have a confirmed pregnancy & was bleeding clots then this can indicate a miscarriage but you need to see your Docctor to confirm this with him. However if you was not pregnant but experienced clots during your period for the first time, then this is not caused by a miscarriage. Clots during a period is perfectly normal & may occur every period or only once a year. Its different in each Woman.
You have had a very heavy period with large clots and you have been passing some clots that look like raw steak Do you think that you have had a miscarriage?
During a miscarriage, the tissue is usually clots that are a grey or pinkish colour & sometimes you can see veins. However it is possible to pass large black clots during a miscarriage. It's possible you could have a miscarriage but it depends if you was having pregnancy symptoms. You may simply be having a unusually heavy period for you & passing large clots because of this. Antibiotics can sometimes cause the symptoms you mentioned…