Missing period.

I see these posts all the time but I see now why people reach out to this community... My period is often irregular and I'm currently 9 days late. The weird thing is that I had all my normal period symptoms. Even with an irregular period I can predict to the day when I start because of the symptoms I have. But then my period never came. I took 2 pregnancy tests 3 days apart and both are negative. My cramps came on super strong, achy breasts and increased appetite... But no period and now those symptoms are going away.

Anyone have any thoughts or clues as to what is going on? Dr appointment next week...