Your haplogroup likely goes back several thousand years. It's not at all inconceivable that people with the same haplogroup will be related to you on both sides. In fact it's quite likely. My paternal haplogroup is one of the most common in NW Europe and the UK. A high percentage of the British population have the same haplogroup. Only by taking a Y-DNA test can you determine how many Y-chromosome mutations there are between two people with the same haplogroup, which can indicate the genetic distance between them.
