2nd chemical pregnancy in a row?!

Emma ❤️💛💚💙💜 • Me and my wife are TTC baby number 2 via artificial insemination! :)
I got the results back today from my beta HCG and it's not good news. My levels went from 16 to 17 in 48 hours. 
This is the 2nd month in a row now and in total my 6th miscarriage. My doctors are absolutely rubbish and each time say they will try something else but never actually do. My highest recorded HCG count last month was also 17. 
I'm guessing I have problems with implantation. Does anybody have the same problem??? Or anyone know of anything I can take??? 
Any help is much appreciated, I'm losing my mind here!! :(