Hello....first thing you should know is- infertility means unable to concieve even after one year of unprotected regular Sex...since you had protected sex its hard to diagnose....if you used condoms occasionally it may be due to numerous causes, in womens- it might be due to uterine abnormality,hormonal imbalance, fibroid in uterus,sometimes infection like T.B would have scarred fallopian tube which might be a cause,certain medications, obesity etc. In men- decreased sperm count, chronic alcoholism,smoking,obesity,premature ejaculation,medications, testicular infection or trauma etc....so get this things checked. You should know that there are 20 to 25% cases where the cause is unknown for infertility....As I already mentioned if you are not concieving for more than one year, you can try invitro fertilisation(IVF) technique which has a good sucess rate....kindly consult a obstetrician regarding this they will guide you further.
your unprotected relation duration is 1 yr, so u r fit in defination of infertility. consult infertility specialist. there is need of certain investigations like semen analysis, hormonal test, sonography, and councelling. dont worry since u have only 1 year infertility u may conceive by ovulation induction or iui