Transfer of domain registrar

My domain domain will be expiring in a month time but already got a reminder from my registrar. I was worried that I might forget to renew my domain. So I made a domain transfer order from my current registrar to another registrar since it’s much more cheaper. I’m expecting the transfer to be done in the next 7 days from now. Till then I would expect my site to be down for 1–2 days as the DNS update would take some time.