9 days late

Hi guys I'm currently 9 days late on my period and still getting negative test. I have not had any symptoms other then being tired  but I have a toddler so I'm thinking it's just from chasing up the last couple days lol. I have been having cramps the past couple days as well. I was wondering when it would be appropriate to call me doctor to see what's going on or any old wise tales to bring my period on so we can move on and try next cycle. Has anyone else ever just skipped a period?