65 Cycle, Spotting or AF?

TTC this month and my cycle is on day 65. 4 days ago I started spotting so I thought it was just AF starting. Days pass and it never gets heavier and I usually have a heavy flow by now. But nope. It’s so light that I don’t need to use any pads. And no I do not have PCOS, doctor confirmed.

I thought it was my month. I’m not stressed and I’m 24.

There are only two reasons either I didn’t ovulate this month or I’m pregnant? But all my tests are negative. What do y’all think?