Thank you for reaching out to us.

This type of procedure, often called a sonohysterogram, is typically performed with instruments less than 19mm in diameter, and so it does not raise questions of becoming niddah through opening of the uterus.

Bleeding for 2-3 days following the procedure is fairly common and can be attributed to trauma from the procedure and considered dam makkah, blood from a wound, and not dam niddah. This means that it should not invalidate the clean days.

In your situation, we would recommend wearing white pantyliners for the end of the clean days, after the procedure. We follow the view that a disposable pantyliner is considered a surface that is not susceptible to ritual impurity, and thus a stain on it does not invalidate the clean days. This will enable you to track any bleeding, while having clarity on your niddah status.

After you have completed counting your clean days, you can continue using a liner or switch to colored underwear. (Learn more about the laws of stains here.)

In your case we would recommend being sure to perform a bedikah on the morning of day six, prior to the procedure. You would then omit further bedikot until the afternoon of the seventh day.

If the seventh-day bedikah has blood on it, it can be attributed to trauma from the procedure and does not invalidate your count. However, in order to have a closing bedikah for the clean days, you should perform another bedikah on the afternoon of the eighth day, in the hopes that it will be valid, and you would then immerse that night. Please get back to us if this presents special difficulty for you or if you are unable to get a valid bedikah on day eight.

Please let us know if we can be of further assistance.