Do I have to wait to try again?

I am going through an early miscarriage. I was only about 5 weeks, 2 days. My doctor said wait until one cycle/period then I can start trying again.

My question is, do they say this to have a more accurate understanding of timing? Or is there a medical reason not to try immediately?

We are trying to time for particular due date months that work better with my job so I really want to try immediately. I’m going to clarify with the doctor after my next bloodwork, but I was just curious about others’ experiences.