pregnant or not?

Sh
So according to this app I am a week late for my period. I've NEVER been late or had a messed up period. The day before I was suppose to start my period I bled like a brownish color in the morning one day and that's it. Idk if I should test or not? I've been very nauseous lately and can't stand smells but I also have some health problems so nausea is normal sometimes for me.