think I may just be hormonal as due on period!!

My partner and are in the process of buying a house, we've both discussed starting a family soon once all moved in.
I really couldn't care about him going out in the evenings and weekends for drinks with his friends, but now he's just said him and his friends are looking to plan to spend a month in America next year, I said to him maybe in years to come when we've settled into our own house, have children etc we could go to Disney Florida for 2/3 weeks, but he said 'if the boys are going, I am'
I don't want to be at home on my own for a month, I know he should miss out, but he acts as though he's still 18 with not a care in the world.
Am I overreacting, just tell me if I am!!