Why can't I get pregnant!

Katie
I have one son, who is 6. I had no problems getting pregnant with him. (I was even taking birth control, I wasn't even trying to get pregnant). I stopped taking my birth control 4-5 months ago and I am still not pregnant! I know people can try for years and not conceive, but I'm feeling really defeated. Am I doing something wrong? Is there something wrong with me? All these questions going through my head.