Did you see your doctor/midwife?
I had bleeding all throughout my 6th pregnancy. It was from cervical ectropion. It healed after she was born and pregnancy 7 was bleeding free. Looks like you have a lot of kiddos, and ectropion is more common in multi-pari moms.
I would see my doc though to confirm, a low lying placenta can do that as well and of course can be dangerous.