It is not unusual to experience a longer, heavier period for the first period after having nursed clean for so long.
We recommend giving yourself a few more days to allow any remaining menstrual lining to shed. You can also soak in a warm bath to clean out any old blood prior to the hefsek taharah.
The hefsek taharah need not be completely clear in order to be acceptable. Stains that are yellow or light brown (the color of coffee with milk) with no reddish hue are acceptable. Other shades of brown can be brought to a halachic authority for evaluation.
If the bleeding/staining does not let up, we recommend consulting with your doctor to see if there is a wound or any other cause for the bleeding.
Please feel free to get back to us with any further questions.
B’hatzlacha!