Brown discharge again in week 9 - to EPU again?

In week 7, I had brown discharge for about three days, getting progressively worse, but never being bright red or soaking a pad.

I went to the EPU and they gave me an early ultrasound. Heartbeat was confirmed and everything was in good order. The brown discharge stopped that day. The nurse told me that this was normal in many pregnancies and that I should contact my GP next time. I mentioned this at my booking appointment to my midwife and she said that if it ever happened again, I should go to the EPU again.

Now two weeks later, I felt a little, brief sting on Monday and then on Tuesday evening, I noticed brown discharge again. Still there on Wednesday night now. Again no cramping now, no red blood, no soaking anything. Just this constant slightly brown tinge in my discharge.

What should I do? Is it worth going back for brown discharge? I feel like I'm wasting people's time, but I'm also worried. My 12-week scan is on 27th February, so more than two weeks out.