Thanks for the query.
Your symptoms could be side effects of Yaz contraceptive
As it is known to cause abdominal cramps, spotting and sometimes excessive bleeding.
For more details:http://www.drugwatch.com/yaz/
The bleeding may not be because of abortion
as in that case you will have bleeding immediately or usually within one week.
So you better consult your gynecologist and enquire regarding changing of the brand of the pills or using additional treatment to control the bleeding while continuing the pills.