What Caused Pain During Internal Examination And Tender Stomach?

Hi I am a 20 year old female of about 5"2. I was put on the depo contraceptive injection at 17 for irregular and heavy periods. The contraceptive pills that I tried didn't always work and gave me IBS. I went to the doctor today as I have experienced very heavy bleeding for the past week and I haven't bled in 3 years. It isn't fresh blood and the doctor wants a further appointment with me this week as she is worried as to why the internal examination she managed to do was painful and the pain took my breath away. My lower stomach was also tender. She mentioned that I may have damaged my cervix and/or fallopian tubes. I am really worried and unsure of what this means and It has only just sank in. any help would be amazing. thank you