I have it as well and at this point used the same head for 5 months. There's no visible deterioration and I exceed the recommended brushing time by doing 5 instead of 3 minutes.
Why exactly is the head only good for 3 months?
[1]: https://www.colgate.com/en-us/oral-health/brushing-and-floss... [2]: https://riverrundentalspa.com/brush-teeth-too-long/