Why Am I Still Bleeding After Abortion?

hi! i had a early medical abortion on the 26th of December 2010, bled ever after until the day I was recovered in the Hospital and doctors told me I still had left active pregnancy tissue inside the uters. On the 27th of January I had the surgical procedure and I didn't bled for about a week. I started straight away the pill and started to bleed again ever since especially after having sex. Is not an heavy bleeding, tho not even just "spotting". I've been to the GP who told me to have a pregnancy test done, which was negative. So he told me not to worry that things are going to stabilize in time...but still...seeing blood everyday is unconfortable!Please tell me what you think...
thanks,

martina