Endometrial lining was 1mm 7 days post ovulation- periods are very light, 2 miscarriages, hsg shows abnormal uterine shape- could this be asherman's?

Yes, Asherman's: Asherman's syndrome is adhesions of the uterus. The adhesions form usually after a procedure like a D&C for miscarriage. Adhesions are areas where there is no normal endometrial tissue cover that will grow to allow for pregnancy implantation or periods. Treating this can be difficult and take time to heal. I recommend you seek care with a reproductive endocrinologist.