Late Period- Negative Tests

I’ll try to keep this as short as possible... My period always comes between the 15th-18th of each month. We tried very regularly to conceive around my ovulation days. I was taking ovulation tests during that time and never got a for sure positive Test but I did have one that might have been positive and also had other symptoms of ovulation. About 5ish days after my ovulation window I had spotting. I have never had spotting between periods but I didn’t want to get my hopes up. I took a pregnancy test in the 16th (1d after my period window) it was negative. I took another on the 20th. Also negative. I took a third one on the 23rd. Still negative. Here it is on the 27th and still no period. I have NEVER been this late on my period. It’s always, always, always been very regular. I don’t know what to think at this point! I want to go buy more tests (maybe a different brand?) and take one tomorrow.. has anyone had something similar happen while TTC? I don’t think I’m pregnant but I also want to get my period so my cycle starts over and we can try again!!