Hello, and I hope I can help you today. Unfortunately, for most women close to age 40 the most common reason why women have irregular periods are due to hormonal changes. Furthermore, the other symptoms you are describing such as right-sided pelvic pain are not consistent with pregnancy. It was good that you did a blood pregnancy test just in case, as women who do get pregnant after tubal ligation art increased risk for ectopic or tubal pregnancy. However, having a lump in your groin, frequent bowel movements, and bloating may have absolutely nothing to do with your menstrual cycle. If you are not pregnant, there is no reason that you could not see a doctor at this time if you are in pain that you might get a diagnosis and some relief. Just keep in mind that many of the symptoms you are experiencing may be GI related and have nothing to do with your skipped menstrual cycle. Certainly, if you experience any fever greater than 10 1°F or 38°C, nausea and vomiting, pain radiating to your bellybutton or notice that the pain is increasing over time rather than improving, you should seek medical care right away or go to an emergency room, as these can be symptoms of appendicitis. So again, as long as you are not pregnant it most likely is a coincidence that you missed your period and develop the symptoms around the same time. You certainly should not wait to see a doctor if you are still in pain and especially if the pain is increasing as these can be symptoms of appendicitis or something else more serious. I hope I was able to adequately answer your question today, and that my advice was helpful. Best wishes, Dr. Brown