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It is not likely to be due to cesarean section, as there is a long time interval between the two events. in the current situation the number one possibility to exclude is pregnancy
& second is infection. I suggest you should have a pregnancy test preferably a blood test
& a trans-vaginal ultrasound
. These two tests are likely to give you some helpful clues about the current situation.
You should see a doctor & report the above. Doctor may do a swab test as well to exclude the possibility of infection.
Hope this clears your concerns.
Wish you good health.