One halachic issue following gynecological procedures is the size of instruments used, since instruments of a certain size inserted into the uterus are presumed to bring on niddah status by opening the uterus. In the case of a standard hysteroscopy, the width of the instruments used are well under the 19mm measure used as a criterion by our site's halachic supervisor, Rav Yehuda Henkin. Thus, assuming standard instruments, this procedure itself did not render you niddah.
While some poskim maintain that bleeding due to injury in the uterus itself is dam niddah and not dam makkah, the position of Rav Henkin is that such bleeding is considered dam makkah and would not render one niddah. Thus assuming your doctor confirmed that removing the scar tissue from the uterus caused trauma and uterine bleeding, you may disregard bleeding for about a week following the procedure and it does not render you niddah.
If the bleeding continues until the time you expect your period, you may no longer attribute the bleeding to dam makkah, and must assume it is considered dam niddah at that point.
Anytime you become niddah, whether it be from a flow, a stain, a procedure, etc., you are always required to wait the five day minimum from when you first entered the niddah status.
Please feel free to get back to us with any further questions.
Refuah Shleimah!