Week 8

I’m 8 weeks today and I threw up for the first time yesterday morning but since then I havent. I have not had any symptoms yet so far besides sore boobs but they have not grown any. I had a miscarriage in the past and I keep thinking what if the baby stopped growing or something. Can’t anyone tell me how long a fetus can stay in the body before you being to miscarry? I can’t wait for my doctor appt 😫 just really worried and keep having dreams about miscarrying again.