Late cycles?

I’ve always had a super regular period, but since we have started TTC 4 cycles ago, it’s become irregular. The first cycle of us trying it was 5 days late. The second it was 16 days late (and I thought for sure I was pregnant 😩). 3rd cycle 6 days late... and now this current one, today marks 3 days late so for.. I’m just confused on why this is happening. I keep getting my hopes up every time it doesn’t show 😭😭