12w4d and brown discharge

C.

I am 12w4d and i have some brown discharge, mostly when i wipe. I read that it's old blood, but how old could it be?

I had a scan at 8 weeks and everything was fine. Where is the blood coming from?

About a week ago i had a small cramp when i lifted something. Could this be the cause?

It's my second pregnancy and i only had brown discharge in my first after the implantation bleeding.

Could this be caused by intense and frequent coughing?