I need some advice please

A bit of a back story: 5 miscarriages, ttc for nearly 4 years. We’ve had a break for nearly 6 months from actively trying, but we’re not preventing. I needed it for my healing and mental health and it’s helped so much.

I haven’t even thought about pregnancy in months, but this month I started noticing symptoms that I couldn’t ignore. Feeling nauseous, loss of appetite, everything smells strong, mouth ulcers. So as i’m on cd31, and AF was due between cd28-31, I took a frer today and got bfn.

I’ve been cramping like I do when AF is about to arrive, and as I got a bfn on a frer I took my mefenamic acid painkillers ready for what I assumed was AF, as I typically start in the afternoon. But no sign of AF. The cramping has settled. But the last 2 times I’ve been to the toilet, I have pale pink mucus and a tiny bit of brown, when I wipe. This isn’t typical of my AF, I normally start with red straight away. So this is something I’ve only ever experienced in my previous pregnancies.

What do you think this could be? I’m now late, with a bfn, intermittent cramping and pale pink mucus. Could it be late implantation- As I wasn’t tracking maybe I ovulated later? Or just a weird AF cycle? I really don’t know what to think.