Irregular periods... longer cycles... help!

Hi friends!

So long story short i have had irregular periods since i for my period when i was 16 (i am 30

now) they have come every other month forever. sometimes they come every month, some times every two. a few times skipped more than that. i have an under active thyroid which i am

on medication for but that hasn’t affected my periods. the past few months, my husband and i have started not, not trying for a baby (just going with the flow and not over stressing about when, just not using protection) i went to the dr before this to get a preconception checkup and asked her to check if i will have issues conceiving. they tested for PCOS (i think) and other hormone levels and everything came

back fine. (no cysts either)

i am here because the last time i got my period was october 18, which is later in the month than usual. if i was supposed to get my period around the 18 ish of december, and i’ve had serious cramps the past week or more, and i haven’t gotten it yet. my cycle seems to be getting farther apart which makes me nervous... i will probably write to my dr and see what she says. anyone have any of the same issues? (also i took a pregnancy test and it’s negative) thanks for the help!