HCG shots and pregnancy

Mi

Hey everyone.long story short, I've had 3 miscarriages in the past year the last being early January this year due to a chromosome problem and partial molar pregnancy. My dr recommend tracking my cycles and avoiding getting pregnant for 6 months. Somehow I must have missed tracked and ovulated earlier then I thought and found out I was pregnant again last week. My specialist is putting me on progesterone injections AND HCG injections at least through the first trimester. I've done progesterone injection but never heard of HCG shots. Anyone had experience with these in pregnancy? Any success?