Lower Abdominal Swelling and Pain

Hello,

     I have been on the NuvaRing for a few months now, and I usually rely on the pull-out method as well for back up protection. Last Sunday, my partner ejaculated inside me, and I am wondering if I there is cause to worry. I am in the middle of my cycle, so if the NuvaRing failed to prevent ovulation, I may have a pregnancy problem. My main cause of worry is swelling and slight pain in my lower abdominal area. I feel bloated as though I would be starting my period soon, but I am not due to begin until about a week to ten days from now. Any suggestions or advice would be appreciated.

     Thank you.