I am 20 and i have a 2 year old. i have been trying for a year and a half for a second child. and we have gotten my husband tested. should i see a doc?

The specifics: The cited average is 6 mo of trying before a desired pregnancy. If you try for a year or more without luck, it may be time for you and partner to be evaluated at a fertility center. Past success is hopeful but does not rule out a change in status for either parent. If they find an issue in either of you they can work to fix it or educate you on your options.