We are sorry that you weren’t feeling well after the procedure, and wish you a refuah sheleimah.
This type of procedure 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.
As your doctor noted, bleeding is fairly common following saline infusion sonohysterography. Bleeding for 2-3 days following the procedure can thus be attributed to trauma from the procedure and considered dam makkah, blood from a lesion, and not dam niddah. This means that it should not invalidate the clean days.
In your case, assuming that you performed a bedikah on the seventh day before the procedure, your clean days are considered complete as of Friday night and you may immerse on Motza’ei Shabbat if you feel up to it. Even if you don’t yet feel ready for relations, immersion is permissible for the purpose of other forms of physical closeness.
In the interim, you should not do any further bedikot, and you should change to colored undergarments. For the near future, we recommend taking precautions to avoid staining questions, and taking care with toilet paper.
Please let us know if we can be of further assistance.