I Am Currently In A Relationship With My Boyfriend And

I am currently in a relationship with my boyfriend and we've been going strong for 2 years. We've only just confirmed that his great grand mother and my great grandmother are sisters, so that makes us third cousins I think? I don't know what to do. Is it wrong to continue seeing him? If we were to continue dating and end up getting married and having kids one day, would there be any medical problems with our kids or any risks that we should be aware of? I'd really like an unbiased and honest opinion on this please!