Should there be a spark?

When I first got with my boyfriend, 5 years ago, I was hesitant to date him. Can’t really pinpoint why but I was. When we kissed it wasn’t like magic or fireworks. I felt butterflies for him bc I loved him but I don’t feel like there’s ever been a spark between us. Buts he is my best friend. And I love him with everything. He got me out of a really bad time in my life and we currently live together. And have for 2 years. We don’t fight much at all. Just a little bicker here and there. I do most of the House work and I clean up after him pretty often. We are both only 20 years old. So we are still young, but I’ve felt like over the past few years I’ve been finding out who I am and what I truly care about. He tends to be pretty negative and self centered sometimes. I can be pretty negative too. But lately I’ve been want someone to help me up and not complain with me. He doesn’t like to talk about deep topics and I love to do that. He’s not a big fan of holidays but he has every reason for that. Sometimes I wonder if there’s someone out there who is better for me than he is. He’s truly my best friend and I love his family and he’s so accepting of mine. Our future together would be just like I’ve wanted. But I’m afraid he’s the wrong guy. I would be content to stay with him forever but is content enough? How do you know if you’re settling? This is so hard and I really don’t know where I stand. I haven’t talked to him about how I feel bc I want to know how I’m feeling before we talk.