CD 20 bleeding ?

Amie

Hi, just wondered if anyone could help! 

I'm very regular every month ( 26/27day cycle ) 

It is Day 20 today in my cycle and I woke up this morning with a fair amount of brown discharge. It has now turned a pink/ red colour. It is not heavy at all but seems quite a lot when I wipe. 

I also have a really strong metal taste in my mouth.

Does anyone have any ideas ?