I am 30 yrs old. how long should it take me to conceive? been trying for 4 months

6 months: Generally, in someone your age, infertility isn't diagnosed until you've been trying for a year or longer. Having said, that, a year is a really long time when you want to have a baby. Wait another 2 months, and if still having unprotected sex around 9-14 days after the start of your period, then make an appointment with an ob/gyn. Remember 1/3 of infertility due to male and 1/3 unexplained.