I am 5 weeks pregnant and I know this question will sound really weird I am extremely embarrassed to ask but don't want to lose my baby. I have one child I am white and my child is white I have been pregnant 4 other times by another nationality and always miscarried and this time I am also pregnant by a different nationality and want my baby very bad but worry same thing will happen is there a medical explanation or anything I can do to stop a miscarriage??

No, just being another nationality will normally have nothing to do with it. There are mix nationality babies all the time.

After each miscarriage when you talked with the doctors, why did they say you did.
After this, have you discussed this with your doctor, have you had a complete exam ?