Late period

Gloria
Hi I was supposed to get af a week ago today and has yet to come! I have been pretty regular since March so I'm not sure if I should go back to my gyno or to our fertility specialist and see what's going on?! I've also taken multiple test and know I'm not pregnant. Any advice, I'm so sick of this up and down roller coaster! I was ecstatic not to get my period then to realize it was for nothing ;(