Help... Relationship advice needed!!

So me and my boyfriend have been together for 4 months now, and I'm getting really bored with our relationship. The guy im with is so amazing and so down to earth, and knows how to treat a women, and he never fails to make me smile or laugh, and our relationship is so amazing, he really is my best friend; but sometimes I just get bored with it all and want to break up with him. This is also how me and my last boyfriend broke up, I got bored with the relationship after 6 months and we broke up. I really don't us to break up, because of how well things are going, and how well we work together. Will someone please help me!!!!!!