Miscarriages

I've seen a lot of girls I went to Hugh school with on fb have miscarriages. One even had a still born. My bf told me two of his ex's had miscarriages but he doesn't know exactly how far along they were. I'm really concerned because this is my 1st pregnancy. He said they weren't going to the doctor or taking prenatals. I'm 8 weeks now but I want to wait til 10 to set my appointment since my insurance hasn't kicked in. When is it safe to stop worrying about miscarriages?