Help, anyone going through this?

Dawn

So for the past two years me and my boyfriend have been TTC with no luck. He has been told he has low motility and we are working with it. I also had to have my cervix burned off due to CIN3 over a year ago and everything healed great. My problem is that within the last six months, I've had four chemical pregnancies. Is there a reason why ive had so many or why they won't implant?