How Can I Tell if I'm doing the Right Thing?

It seems that I ask myself this question all the time. Right now I'm wondering if getting back with my ex boyfriend is right for me. We were together for 4 years, but I was only 19 when we started dating. Since we've broken up, we've remained friendly (since our breakup had nothing to do with arguing, but merely the fact that he was going to Cali for a fellowship). At first I thought that his taking this fellowship was not taking my feelings into consideration, but as I grew up, I realized that getting this fellowship was a fete in itself and he had to take it for the advancement of his career. He wanted to get back together, but I felt that I was with him for 4 years and I wanted to "explore" my options. We got back together about a month ago, and sat and talked all night about "us" and where we wanted to take our relationship to. We seemed to have similar goal (we always did) and basically wanted the same things. What bothered me during our relationship was put aside, due to age, inexperience and not being mature enough. At first it was dinners, and fun dates. We used to love to get up on Sundays and go to the book store in the village for hot cocoa and then watch the old chinese men practice Tai Chi. We loved to go to the international market in the city and look at all the foods from around the world and eat things we would never consider eating. Michael brought home Dr. Suess books and read them to out loud, knowing how much I loved to read Dr. Suess to my nieces and nephew. I was hysterical..... having my adult, serious, doctor boyfriend reading Dr. Suess! Everything was and is great. So why, when I get home from being with Michael, do I question if this is the best thing for me? Am I destined to always doubt myself or perhaps I'm just not ready to settle down and this is my way of not having to make decisions about my future? I wish I could just chill and let my future find me, instead of me seeking out my future........