Period not coming

I was suppose to start my period on Monday, it hasn’t came yet. I have sore boobs, but not period sore, I have cramps, I eat like I’m on my period. I took a test this afternoon and it said negative, my friend told me him it doesn’t come by Sunday to take another test. I haven’t been this late, I don’t feel like I’m on period as well. I could be stressed out from work but I exercise every day so I’m not stressed and this happens. I’m not sure what to do at this point. If I should talk to a doctor next week? Or give it another week