Mandy - I am so, so sorry for the loss of your 3 special angels. m/c is horrific and only gets worse the more you have.
I have both difficulty concieving ( ovulation disorder) plus a loooooong hx of m/c ( 7 baby angels to date) so I truly know how you feel
I would NOT stand at all for a lack of testing because you've "only" had 3 losses. My FS was happy to do all the standard recurrent m/c tests ( including karyotyping on DH and I) on me after 2 losses. Nothing showed up on the tests but at least we had done them. I was fortunate to carry the next pg to term and deliver my precious DS. Since him, I have lost a further 5 babies. One was confirmed to have trisomy 15 but all the rest "unexplained". I did pursue further testing by a specialist in Sydney late last yr which did show high levels of NK cells so am on prednisolone treatment this pg. This is an IVF pg which was twins but i sadly lost my 7th angel 1.5wks at 8wks ( after seeing him/her alive and well only earlier that day).
Not sure if the treatment is helping the other twin hang on or just a really, really tough baby.
Bottom line,,, you CAN have a successful pg even after many losses BUT, there are plenty of conditions that may require treatment to help you get there.
I would either push your Dr harder or find another one. You should not have to suffer another loss to be taken seriously.
BTW, have you have any of your babies tested for chromosome disorders? Is not a standard test done on "products" after a D&C but is invaluable in trying to determine cause of m/c.
Please PM me if you w]ant anymore info and stick with BB, It will provide you with a wealth of knowledge as well as endless support from women who know what you are going through