Is it safe to take letroz 2.5ml for conception purpose ?

Hi I am 28 yr old women, my weight is 58, height 5.2, from last o ne year we are trying for baby.. my period was irregular, my doctor sugget me thyroid test and that is 40.19, after taking thyroid treatemt for 2 months my thyriod is normal now and now from last 4 months my periods are regular. but i did nt conceive. my doctor now suggest me letroz 2.5ml from 3rd day of my period for 5 days. and after that she will do my ovulation study. my concern_ is letroz medicine is safe to take ? i read negative and harmfull effect of letroz medicine on internet like....... Letoze -- is internationally approved for the treatment of breast cancer in post-menopausal women. gynecologists all over the world not to misuse it for female infertility . Research on 150 pregnancies has shown that babies born to mothers who had consumed letrozole to increase fertility have suffered from bone malformations, cardiac stenosis and cancers. should i go for letroz or not please suggest me m very confused.