As long as you were able to perform a Day 1 bedikah on Wednesday before the hysteroscopy, you may omit bedikot up until this coming Tuesday (Day 7 of the clean days). You must perform a bedikah on Tuesday in order for your clean days to be valid. The staining should have cleared up by that point. Even if you are experiencing mild staining on Day 7, you should still perform a bedikah and bring any problematic stain to a rabbi for evaluation, explaining that it is your Day 7 bedikah, and you recently underwent a hysteroscopy that caused staining. In addition, you may shower normally (not purposely cleaning yourself internally), wait 10-15 minutes, and then perform the bedikah to help wash away any old/dried blood from the external vaginal area.
In the event you are unable to perform an acceptable bedikah on Day 7, and you did not perform any other bedikot after Day 1, unfortunately you would have to restart your clean days.
Please feel free to get back to us with any further questions.
B'Hatzlacha!