The other poster is right, that you won't know for sure until the official beta. Some embryos seem to be slow starters. And I hope that is the case for you!
But I also want to say that I 100% don't blame you for you for thinking about the tropical vacation if this doesn't work out. I took several of what I liked to call "fertility vacations" in between cycles. Part of what makes this journey so hard is feeling like you're putting everything enjoyable in life on hold, so let yourself have whatever you need to recharge and keep the faith. I wish you all the best!