Trying clomid. When to start?

Hello I’m new here. My doctor prescribed me clomid the problem is he had to cancel my appointment but he did prescribe clomid to start 50mg cycle day 5-9. The problem is I didn’t get to speak with him and my cycles have been between 30 days to 32 and I “supposedly“ ovulate on day 18 that’s what the ovulation tests have been positive on. My question is... would it be correct to start clomid on cycle days 5-9 with my info? Ty!