Late Period

Has anyone else experienced this? Per glow, AF was supposed to be here 9/9 but she's a no show. Been having cramps front and back and a little pelvic pain since last Tuesday so I just figured I was a few days late bc sometime I'm like 2 or 3 days late never 6! I took a pregnancy test but was negative. I don't know what's going on or how long should I wait to contact my dr bc maybe AF might show just really late. Any info would be good info! Thanks!