That's a bit leap from pain and long cycles to not having another child. Our bodies shift and go through changes. Not sure when you came off of birth control but it can take a while to get back to normal. I personally had a hormone issue/thyroid issue and had periods only every 3 to 4 months for a year and a half. It righted itself over time and I went on to have 2 kiddos. So, see your doctor if you've been trying for over a year (it takes a year for the average couple to conceive) but try not to worry. The pain could be a simple, non dangerous cyst that most women have in their ovary at least one time in their life. So discuss it with your doctor at your next check up or if the pain intensifies, give them a call. good luck