We are sorry to hear of your difficulty conceiving.
For procedures that enter the uterus, the size of the instrument that enters is halachically significant. Instruments larger than a certain size render a woman niddah even if there is no bleeding. Opinions as to this size vary. Our site’s rabbinic supervisor, Rav Yehuda Henkin, rules that an instrument with a diameter of less than 19mm does not make a woman niddah. Since a hysterosalpingogram uses a narrower instrument, the procedure itself does not make a woman niddah or invalidate her clean days.
Following the procedure, there may be some brown discharge (from the dye) or even some bleeding (which is usually dam makkah from cervical trauma). External staining may be attributed to dam makkah and disregarded. However, it is necessary to have one acceptable bedikah on day seven of the shivah neki’im, which may be complicated by the procedure.
You should perform bedikot as usual up to and including the morning of the procedure. Following the procedure, you may omit bedikot until any bleeding subsides, taking care to perform a bedikah on day seven.
However, if the procedure is planned for later on in the clean days, you may have to delay your day-seven bedikah (and thus immersion as well) until the bleeding subsides and you are able to get an acceptable bedikah. As long as five days do not pass without a bedikah, your clean days will remain valid. For example, bedikot on days one through five, followed by a final bedikah on day ten would be considered a valid set of seven clean days. If it seems like this delay would cause you to miss your ovulation window, please ask a specific halachic question about how to proceed.
If the procedure is planned for day seven itself, you should perform your morning bedikah prior to the procedure and then omit the afternoon bedikah. In this case, even if you experience staining following the procedure, it may be disregarded and you may still immerse as scheduled.
You may also find it helpful to consult a Yoetzet Halacha Fertility Counselor. (This is a free service, details here.)
Please feel free to get back to us with any further questions.
We wish you much hatzlacha!
This response was updated on 20 October, 2020.