I hate when my cycles shift...

The past few months glow's algorithm prediction for my period was very accurate--maybe 1 day off here and there. Today I was supposed to start my period and I'm late. I took a hpt two days ago and it was negative. I am wanting to wait to take another test to see if AF shows up. But now it has shifted my cycle, showing my fertile window was a few days later then what I thought it was this past month 😒 I'm having normal period symptoms, which makes me feel like I'm out for this month. It's just frustrating when you're trying to conceive and everything shifts around!!