You don’t have to buy individual health insurance for a month if you don’t want to. This isn’t required to comply with the terms of the Affordable Care Act (ACA). However, you may want to buy a short-term policy in case of illness or injury.
The great thing about COBRA is that you have 60 days to elect it, and it will cover health claims retroactively within those 60 days. So you can wait to decide on COBRA, and if you have a claim you can elect COBRA for a month and have the claim paid.
Read about the basics of health insurance and what is required under the ACA here.