effects of having menstrual cups in for months?

Hi,
Welcome to ehealthforum,
If you leave the menstrual cups inside for longer duration than recommended, chances of infection, PID, cervicitis are possible. The symptoms that you describe could be suggestive of infection. Do not delay in visiting your doctor/gynecologist for further evaluation. Get vaginal swab/smear test done to look for causative agent. Delay in taking treatment can lead to PID (if not occurred already) or worsen it leading to future infertility problems. Get started on appropriate treatment as indicated by the examination findings and investigation results. Consider requesting for prescription of a Probiotic (to be used after you finish with taking the other medications) to restore the normal vaginal flora to minimize re-infection/repeat infections or opportunistic infections. Be in regular monitoring and follow-up with your treating doctor/gynecologist and report any new/abnormal symptoms immediately. Drink plenty of water. Take adequate rest. Maintain healthy diet and lifestyle. Avoid vaginal douching, use of harsh soap or perfumes in the area. Use loose cotton undergarments and avoid use of tight fitting clothes. Avoid sweat accumulation in the area. If infective cause is detected, and if you are sexually active, get your partner also treated simultaneously to prevent chances of re-infection, and avoid having intercourse.
Take care.