Pcos and late

I have pcos and I have been having my periods pretty much every month for five months now and I haven't got it yet this month and I'm 6 days late I took a cheap pregnancy test this morning it was negative maybe I took the test to early or my periods are back out of wack anyways I have no clue what I should do or if I'm just over thinking this I have been ttc for almost three years now I need some advice please