J.B.
On my 4th pregnancy I too started bleeding in an alarming way. I was very scared because my first 2 pregnancies ended in miscarriage. I bled on and off for probably a couple months starting probably around 4 months and ended up having a healthy baby girl past 40 weeks. I have had 2 sons and had no bleeding with them... never knew why but heard some friends had similar experiences! Best of luck to you, try not to worry - it's not good for the baby :)