How can i get pregnant at 19?

ok. i dont wanna hear the whole im to young thing i have my high school diploma a graduted from medvance as an medical assistant i have my own place,money and a supportive accomplished husband whos 22 years old we been trying to conceive fpr the past 4 months but nothing :(( we had gotten pregnant once already when i was 17 but when i was 36 weeks gestation i had lost my baby i had to delivered my stillborn baby boy via c-section and well now that we are more matured we want to try again but we cant seem to get preggo any advice of what i or he can do???