Are Scars On The Uterus And Miscarriages Related?

Hello, I'm 29yrs old. I have had 2 full term babies via c-section.Also two miscarriages...the latter of the two being last sept due to a sub-chorionic hemmorage at 15 weeks. I am 6 weeks pregnant now and beginning to spot slightly brown , grainy looking discharge. Also very dizzy. Do you think there may be a link between the scars on my uterus and the miscarriages?