I Am 22 Years Old, I Had A Cycotec Abortion

I am 22 years old, I had a cycotec abortion 2nd week of june, 4 weeks after, I discovered I had a thickened wall (retained product)and hormonal imbalance after an ultrasound I was advised to go for a D&E. I had the D&E last week (11/07/15). So I had a pregnancy strip test this morning (17/07/15) and still test positve. What could be wrong with me ?