9 month old Lab Retrievers

Question
I have 2 black girl labs, 9 months old and I believe they are having their first season. I have noticed small blood spots around the house, which I assume is normal. What is worrying me is that they both appear to be having (sorry about this) loose stools which have tiny amounts of blood in it. My initial feeling is that as they are going to the toilet, blood is discharging at the same time.

Is this the case or should I be worrying?

Answer
That sounds normal.  I hope you are taking stringent steps to keep them away from males at this time.  Do not discount anything as too unlikely for them or a male wondering by to do to get together.  Such accidental breeding can be a big problem.  

Your question suggests to me you have not met your obligation to educate yourself on dogs or get your pets spayed.  Failing to do so leads to no end of problems.