Can Pre Ejactulation get you pregnant?

Hey ladies, I was just wondering if any of you got pregnant using the withdrawal method. I had unprotected sex with my partner and we used the withdrawal method. I took a look at this lovely app and saw that I was 33% fertile the day we had sex. Usually a week before my period I get a load of symptoms leading up to my period. This month I don't have any symptoms at all. I randomly got this sharp pain in what seemed like my left ovary area. I called my sister about it and she said it sounds like it could be an implantion pinch. I would be okay with a baby but we are not TTC. Can anyone give me a little insight ?