Vacation Time

Hi everyone I’m 4 months pregnant and my boyfriend has been on 3 trips with his cousin since they are close and I’m always excluded. I’m planning a trip in October after my birthday to an island to get away with my friend without him. I’m due in the beginning of July, and I feel like I should be able to get away and have me time to myself since I never get to. Am I in the wrong for planning a girls trip for my birthday without him? He will have to take time off of work to watch the baby but in the last 4 months he’s been going on trips and taking time off of work last minute so it shouldn’t be a problem. Am I selfish?