That's common. Kevin Bacon and Kyra Sedgwick found out they were like 6th or 7th cousins when they appeared on Finding Your Roots. We found out my brother and his wife are also distant cousins, like 8th cousins or something. My parents are also cousins, as they're both descendants of Edward III. But like 20th cousins or something. I'm sure they're actually more closely related than that through some branch we just haven't found yet. But if your families share similar histories, there's bound to be a relationship somewhere back. But that doesn't necessarily mean you even have any shared DNA, thus not blood related, due to random gene recombination, since we may not even inherit DNA from the shared ancestor, and even if you do, it's likely small, and not like it would affect offspring. Heck, back in medieval times, some people married first cousins even, which is illegal in the US in almost all, if not all 50 states. However, many states still allow second cousin marriages. Being 6th or 7th cousins is fine.