I have a child , but am afraid what if i cant have another

Generally if you've gotten pregnant before, you can get pregnant again.  That's not always the case, but if you go more than a year trying without luck then you should see a fertility doctor.  Trying to plan exactly when you are going to have a baby is tricky.  Babies come when they are ready, some are very early, some late, some right on time.  You can try to get pregnant when you want to conceive, but I wouldn't hold yourself to that too much and risk letting yourself down.  Try using a conception calendar.  It factors in your periods, how long they last to estimate when you want to conceive to have a child during April.  You can find them online, the one we used was on this site in the fertility section.  Check it out.