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So this is not the first time I've noticed (maybe three or four) but around mid cycle so day 10-12 I get some black tar like discharge. It doesn't smell and I don't get any pain so I tend to think it's fine. I have n IUD in case that makes any difference.
Do you take the pill? I used to get this all the time on cerazette and went to the GP. Smear came back normal, swabs all normal, she couldn't see anything that would be causing it on my cervix. I stopped the pill shortly after and all midcycle bleeding immediately stopped.
I would check with the GP but usually black blood is just your womb clearing out old blood