When’s a good time to start trying?

Hi All, i am 20 years old. All of my friends have recently either had a baby or just got told they are pregnant. even people younger than me. I do feel like i’m a bit behind in the whole starting a family thing. I do want kids i really do. My fiancé and i tried for a couple of months but both got sad seeing the test being negative so we just sort of stopped trying all together. before we start trying again i just wanna know what the perfect time is.

(my fiancé and i have known each other for almost 7+ years, been together for 4. i don’t want to see any mean comments about being engaged at my age!)