My boyfriend [26/m] told me[23/f] he plans to marry me. I don't know what I do? What could this mean?

I ask this because my boyfriend of a year said this to me yesterday and it caught me off guard. We both believe in marriage and are in love. He talks about our future me than me. He is super sweet and usually means what he says. I have met his family and he's met mine, everything is great when it comes to friends and family. I'm 23 and he's 26 he has finished university and has a good job, I am almost done school and would prefer to be married at 25, but he might want sooner. He has planned for us to go on a trip to Niagara falls in 3 weeks for a wine tasting, fine dining and a nice room with a jacuzzi and a king size bed. Should I prepare to say no to a possible proposal on this trip :/? What do I do?

Are there any men who have done this and are now married or engaged to their girl? Also, are there any married or engaged women who experienced this before their man proposed. Could a proposal I'm not ready for be under my nose?