Community medical question

I’ve had irregular periods since the beginning. My cycles are always irregular — sometimes they come after 3–4 months and sometimes after 7–8 months. After marriage, I conceived through treatment and now I have one son. I want to conceive again. My last period came on 15th November, and that also came because I took Duphaston. I did my tests on the 2nd day of the period because my doctor recommended it. Now I want to know which medicine I should take next to help me conceive.