OK I've got a question that hopefully someone may be able to help me with.

It's been 3 days since AF, and when I go to the bathroom and wipe, there's a small amount of spotting that is very light dull brown..... I was wondering when implantation bleeding usually occurs. And I thought that implantation bleeding is usually light pink.... any help would be greatly appreciated. We have been TTC for a few months now after we miscarried with twins last summer. I've also had a few very high risk pregnancies in the past after carrying a baby girl until I was 7 1/2 months along and got pneumonia in both lungs which turned into ARDS causing my lungs to collapse and my body to go into septic shock. I was in a medically induced coma and on a ventilator so they put me into labor because my body couldn't handle surgery, so they couldn't do a c section and they couldn't treat me without harming the baby. So she was still born and I remained in a coma and in ICU for 5 weeks after that. So I'm scared to death that I may miscarry again....