Do you think our love is real? do you think we will last?

My boyfriend and I have been dating for a year and a half, and its great. We are almost 18 and we just get along so well. We talk about getting married and swore we will never leave each other. He tells me how much he loves me everyday. We even swapped virginities when we had been together three months. We used to argue, but we fixed things. He left me for a couple weeks because I smoked with guys but I've changed and he dumped his week-long girlfriend to get back with me. Do you think we will last?