I am currently 4 days late for my period. When should i take a pregnancy test?

Nothing has changed in my life (diet or exercise), and I'm not stressed out or anything. I also don't feel like I will be getting my period soon.(I always have a strange feeling in my stomach but never have had cramps)

Edit: Also, I have no idea if I would have any soreness in my nipples because I got them pierced almost a month ago and they are still healing.