if a couple doesnt conceive in 1 year of unprotected intercourse, then we call it infertility.
You need to meet a Gynecologist FIRST.
You will be guided to do some tests like
thyroid tests, blood tests, hormone tests and semen analysis.
The treatment of infertility is aimed at allowing a sperm to meet the ovum at optimal time.
while sperms are deposited in vagina at every act of sex, the ovum release in female's body is usually not acompanied by any definite signs or symptoms,
so usually the patients have difficulty in knowing when to have sexual relations.
But when treatment is started the gynecologist can tell you the fertile period based on calculations of your menses dates, sonography etc.....the couple must plan to have sex on these days as these days are the ones where Ovum release is likely.
when the ovum is released, it is viable ( live) for only 24-48 hours, so there is a need of having sex during these days