Period or Implantation?

Rae
So my bf and I have never had penetrative sex but he fingers me and we do other things. So my period is supposed to start tomorrow and I have had some pinkish brown discharge almost like a period. My mom says that it's just my period starting up slowly but now that it stopped im not sure? We didn't have sex though so I think I'm just paranoid. Any opinions and advice would be great!