Can a person be prone to miscarriage? I know a mother who had 3. Afraid I'll get one. I'm 4 weeks pregnant. Are there any risk factors?

It depends on individual's health actually. I had two miscarriages previously but now I'm alr into my 11 weeks and all is good so far. Don't worry and stress about it, if anything worry you then you can always rest in if you feel more comfortable that way