You are suffering from recurrent miscarriage
including 3rd one.
There are several reasons to be ruled out like blood gr & Rh both of you,genetic cause/chromosomal abnormality,LPD/progesterone deficiency
,Rubella test including TORCH infection
profile,anatomical defect,Diabetes etc.
So need several investigation including blood reports to rule out underlying pathology.Consult with your gynecologist.
Take Folic acid with vit-E supplements in preconception period up to 3 months of pregnancy.Avoid stress,take healthy diet and need proper sleep.