I can't get pregnant!!?

Basically, last September I had my implanon implant removed. My periods started again in November and my partner and I have not been using contraception for a year - hoping to get pregnant. I am charting my ovulation as well as I can! About 2-3 years ago I was told I may have pelvic inflammatory disease, and though they couldnt find any infection I was given antibiotics. If I did have PID I cannot of had it that long. I'm really worrying and I know thats the worst thing for it but I cant help but think something might not be right. My two elder sister both fell pregnant at the drop of a hat and everyone around me seems to be falling pregnant so quick so its killing me that I cant. So I am wondering how long it usually takes to fall pregnant? And if anyone has any tips on how to not stress about it!