Late period

I’m 8 days late and that’s something that’s not really normal. I’ve been late before but only a day or two. I’m getting married in 2 months so idk if it’s stress (even though I don’t feel anymore stressed than normal). I’ve taken a pregnancy test everyday. The first test had a faint line, but both of the digital ones said not pregnant. I have 2 kids and I don’t feel the symptoms I did with them. I guess my questions are has your period been late bc of stress? How long? And do you see a faint line in the test?