Is it still a possibility ?

Katelynn
This month we decided to take geritol. We tried on what glow said was fertile days. 
 
My question is though I took a digital clear blue test a day before af was due and it was negative. I took a first response test when I was 4 days late for my period and it was negative. I had light pink discharge on day 4 of being late then on day 5 (the 5th) and I had dark brown discharge and later that day light bleeding. I started what I think is my period on the 5th and now it's the 7th and it just seems really light compared to normal. (Tmi) but It usually SOAKS a super tampon by the end of the day and even the string would be soaked. Now it's just kind of lighter when I take the tampon out, not soaked, and the tampon still has some white parts that hasn't even got touched with blood. And sometimes when I pee nothing comes out hardly at all. (Usually that's not the case lol!) 
Is it possible that I could have light bleeding and be pregnant?