Mazal tov on the recent birth of your baby!
If you inserted your finger internally (inside the opening of your vagina), even a small amount of reddish blood found on your finger would render you
niddah, since it is treated as if it were a
bedikah. If you only touched the vaginal area externally, and the stain on your finger was less than a
gris, then you were not rendered
niddah since it is governed by the usual rules of
ketamim (stains).
For the future, if you want to check for staining, you may wipe externally with a tissue/toilet paper (
not after urinating) to see if there is any staining. Even if the tissue is stained you will not be rendered
niddah from it, since the
tissue is a surface not susceptible to
tumah.
Please feel free to get back to us with any further questions.
B’hatzlacha!
