Sorry for the TMI, but this has never happened to me before and wondering if this is "normal" spotting?

Today is CD9 and I noticed some dull backache earlier. When I went to the toilet, I saw there was some brown discharge on my underwear. Over the last hour, it's more brown streaks through my CM when I wipe.

Last cycle was our first TTC so I was hyper-aware of possible PG symptoms the last few weeks, and I think the anxiety of obsessing over "am I or aren't I?" may have mucked up my cycle. When AF finally arrived, I had two days of spotting first, which is relatively unusual for me (sometimes I get spotting for a few hours or a day before AF arrives). AF finished after 5 days, then I had another two days of spotting on CD6-7. Yesterday I had nothing at all. Now brown spotting today, and the backache.

Is this what spotting is? Anyone else experience this? Sometimes? All the time?

Thanks for any help. x