There is probably nothing at all wrong with you, don't worry. The amount of time it takes for a woman to get pregnant varies from just one time, to a year or longer.
The ovulation test will tell you which two days in the month you are most fertile, and therefore will provide your best chance of getting pregnant.
If after several months you are still not pregnant, make an appointment with your doctor who can refer you both to a clinic to find out if there is a problem with either you or your partner.
Don't just assume there is a problem with you, it is just as likely to be a problem with your other half.
For now though, possibly start thinking about getting an ovulation test, but more importantly, try to relax and let nature take its course. Stress will prevent you from getting pregnant too so, I know it's difficult, but try not to think of it all the time.
Good luck, I'm sure you'll be a great mother.