Need advise please ladies!

Hey ladies, could really use some advise.

Here's a bit of information first:

- I am 26.

- Went off the pill and have been trying to conceive since May 2017 and have had 38-41 day cycles ever since.

- 22 DPO according to a pregnancy app, but have never actually tested when my ovulation date is.

- AF is currently 7days late.

- I have taken 4 pregnancy tests in the last week since AF didn't arrive. All have come back with a BFN. Not even a faint line.

- Have had on and off mild cramping everyday since AF was meant to start.

My questions are:

- Am I testing too early? I thought something would have shown up on a test by now.

- Are there any other reasons other then pregnancy for why AF is late but still have cramping?

- How long should I wait before going to a doctor if AF hasn't arrived and still showing negative on pregnancy tests?

Thank you! 💜