I have been trying to get pregnant for four months?

I had PID (pelvic Inflammatory disease) approx. 4 years ago, and one of my felopian tubes is somewhat scarred. Do you think this is why I'm not pregnant yet? I have 2 other children that I had before I had PID and had no problem getting pregnant. Anyone else had PID have any similar experiences? How long did you try to conceive? I'm getting so frustrated!!!! Help!