IBS-C or Ovarian Cancer?

Hi everyone! My first post..been around for a while but just reading everyone else's posts to try an identify with them. My history in a nutshell..In my 20's I was told I may have IBS but at that stage very little was known about it and the doctor almost made me feel like I was bluffing..but sent me home with a sheet of paper with foods to avoid like tomato peels, nuts etc. Fast forward to last year when I tragically lost my twin brother to a pulmonary embolism and at the same time my mom was weeks away feom dying of rectal cancer. I developed a pain in my lower left side and saw a GP. After an ultrasound scan (revealing nothing abnormal but an impacted bowel), i was sent for a colonoscopy. This only revealed that I have minor diverticulosis and the GI said he thought it was IBC-C. Long story short...he put me on 20mg Psyllium Husk per day, Trepilene 25mg (at night) and Librax (when needed for pain..which is almost every day). When I get my daily pain..it usually starts with lower back ache when I rise in the mornings, followed by winds. I have my Psyllium Husk in my porridge and only around 3pm do I hopefully have a bowel movement but some days it will not happen and the pain just stays there. When I stand too long I get a gnawing pain down my left thigh as well as the urge to clutch at my lower left abdomen for pain relief. The librax helps only if I can lie down and relax. What if this is ovarian cancer? I ask because nothing is relieving the pain or constipation? Why did it suddenly start last year? I have all these questions. I guess I need to know if anyone else here has experienced this and landed up with the cancer diagnosis?