It sounds as if you had a miscarriage, if you are still having symptoms see your doctor. It is also possible you have a sexually tranmitted disease. Other things are possible but these are the two most likely.
Stable Periods of little change interrupted by brief periods of more change is known as punctuated equilibrium.
Paragard may change the flow, cramping, or duration of bleeding but not the timing of bleeding.
Evolution of man.
it change by the age..