Success stories using letrazole?

Hi everyone

We are very lucky and grateful to have 1 gorgeous baby. We conceived really quickly but now it looks like we are suffering secondary infertility. Had anyone used letrazole and got pregnant? How long did it take? I've got friends who have used letrazole and had success but they also had miscarriages leading to the use of letrazole and their fertility doctors would say a miscarriage is a good thing because it means you can get pregnant. We haven't had a miscarriage thankfully but does that mean there is something else wrong?