Can I measure my carbon dioxide levels at home?

After researching an answer to this, I haven't found one. It makes sense that if we have (in the U.S.) breath monitors for ketotones, alcohol, etc, then we would have one for measuring our personal CO2 levels. Does anyone use one? I found an item out of Australia that measures CO2 called an ICO Smokerlyzer, and several in Great Britain called N-Tidal technology, but nothing here in the U.S.

I am wondering because even though my oxygen sats are only between 90 - 96, I wake up most mornings with a thrumming headache. I drink plenty of water, so I'm wondering if it's CO2 buildup.

Thanks for your input!