This movie was made in the last 15 years or so.
A high school girl and other random people are on seizure medication, and at a certain age get bumps on their foreheads. They somehow find out that they are human form of aliens which are small worm like creatures. Their race passed by Earth in a tiny black space ship the appearance and size of a large black sea urchin and somehow infect 2 men is a space station. They somehow attempt to rejoin their race. At one point a girl who is a member of their race in human form walks into a pond.
It was a very strange movie, but I would like to see it again. Google can't find it.