Dr. Hibberd's answer:
 

No. Women who have had miscarriages, or abortions for that matter, do not face any increased cancer risk. In fact, just the opposite — pregnancy actually decreases the risk of a certain form of cancer, so-called hormone receptor positive breast cancer. A young woman, 20 or younger, who carries a pregnancy to term will have half the breast cancer risk of a woman who waits until she is over 30 to have children. 
 

Pregnancy does change breast tissue because of hormonal changes, and that can cause a slight short term increase in breast cancer risk — particularly in women who have other risk factors for the disease — but it disappears within 10 years of childbirth. 

Breast feeding also significantly reduces risks of all types of breast cancer.