Implantation bleeding or ...

I'm 4 weeks preggers and I m super worried because today i have some brown spotting. It's my first pregnancy and I'm not sure how to identify whether it's a sign of miscarriage or just implantation bleeding. My first gynae appointment is on the 13 May (week 7)... should I just relax and not be worried, or bring forward my first appointment, not sure if it's too early