I agree with Old_before_my_time on it could be so many different things! I would definitely be getting in to see my Dr. because any new or abnormal bleeding should be investigated by a medical professional and in the meantime start researching and have your list of questions for the dr.! We have to be our best advocate for our health...so all the things mentioned above look them up and compare and as you do that if a question comes up write it in a notepad to take to the appointment and ask your dr. Good luck and please do check back in with us and let us know what is found! Thoughts and prayers to you!
Vaginal atrophy from lack of estrogen can cause light bleeding or spotting. If you have/had endometriosis, endo lesions on the vaginal cuff can trigger bleeding. If your vaginal cuff tore, that could also cause bleeding. I cannot think of any other causes. Let us know what you find out.