Old Blood is discharge but no period??

I was expecting AF 3 - 4 days ago. It never arrived and still hasn't.
Today though I had some stringy Brown, old looking blood in CM. I haven't had any of the usually AF symptoms I have, Headaches, cramps etc. And the teariness - can't tell atm if that is af symptoms or everything else going on.
My cycle is usually 28 - 31 days long, so in theory it could still come. Earlier in the month I had HUGE amounts of CM (more than normal) and loads of cramping which is pretty normal so haven't thought anything of it.
We haven't been TTC at all. We use condoms but thats it. So I would say pg is not likely but it couldn't be ruled out completely I guess. Condoms are 100% safe hey.

Anyway, I guess what i'm asking, has anyone ever just had some old blood in CM but no real period and not been pg?? It can still go on to a normal period later on yeah??

(EDIT: Can a mod fix my title please, it should say in discharge not is discharge)

I get that black/brown blood in CM leading up to af each month so perhaps she's just taking her time this month.

I have had it in the lead up a few times, but also the months of anovulation (i was charting so know I didn't ovulate). Other than that I :dunno: