Bleeding hell

For a long while now I’ve had bleeding between my periods. My cycles are regular in that they’re frequent but the length of my cycle is inconsistent, ranging from 24-36 days. 

The bleeding, approx halfway through my cycle, started as a pinkish loss on wiping. It’s steadily increased to a red brown or pink loss that requires me to wear a panty liner, and is still halfway through my cycle. It’s gone from being on one occasion to lasting a few days. This cycle I’ve had a steady small loss lasting 7 days! It is not a period. I do have very mild cramping.

I’ve had pelvic scans +++ and a hsg. I’ve had speculums and smears and swabs. All clear. 

What could it be? Does anyone have any experience of this?

Hsg

Clear Fallopian tubes ✔️

The extra day off work was almost worth the speculum… Almost! 

Now, just give me the drugs already!