1 day until AF...confused...

Hi ladies,

Well my AF is due tomorrow and I did a test yesterday which was a bfn. Anyhow my nipples are dark and swollen and more prominent and I have blue veins all over my chest. Coule this be due to my period coming, pms or do you think there could still be a chance i could be pregnant? I was also having night sweats which i never have...TIA