I have a 2 year old house with a tub sized walk in shower. It has a single handled mixer valve that adjusts for temp but not for pressure (i.e. it's either on or off). The shower head is hand held.
After taking a shower, there will be periodic forceful long drips for about 10 seconds. After a few minutes, this will happen again. It will happen 4-5 times from the time showering ends and about 20 minutes. It does not drip constantly, just for the 20 minutes after showering.
I don't remember if it always did this but I have been noticing it for the past year. Is this normal? If not, what should I do about it.

Thanks for any advice.