Just for full disclosure: Haven't heard any claims of daith piercings coming with any risks, other than the high probability of not having any effect. I have preventative medication with very minor side effects (totally ignorable if I have them in the morning and drink lots of water) as well as painkillers which the preventatives mean I only need maybe once a month instead of my previous frequency being comparable to your pre-piercing results.
I've heard of claims that it's a placebo, but been told it probably isn't, and that in the cases where it works, there's good reason to believe it's making a real difference, not just a psychological effect. Glad you've found something that works for you, and I do think it's worth recommending/considering for others with migraines, even if I don't think it's a good choice for me personally :) so, again, thank you!