Can You Look Like A Relative?

Nina • Proud mommy
Okay so I was told guy A) is my dad which he passed away 15 years ago and I have two siblings from him and the other woman he was with. His kids and I look nothing alike (which I know is possible), but my great uncle thinks they resemble him more than I do. So comes in guy B) (which is at this moment my other uncle) My aunt and great uncle swears I look like him and his oldest daughter. And I looked and I do look like them a lot. My mom won't open up and talk about the fact she slept with both men, and won't acknowledge it stating guy A is my dad end of story. My grandma says it doesn't matter because I'm grown and who cares who is my dad but I do a lot, and so I was wondering if it's possible because the uncle was my dad's brother that is why I look so much like him and his daughter? Or if I should seek a DNA