How to plan a vaca when ttc?

So ill be starting clomid/iui this cycle. Our anniversary is end of June. DH really wants to go on a cruise from PR. That week. I'd like to too but am not sure about if we should? My fears are what if I was to finally get my BFP next mo... Then ill only be about 8 weeks preg and if I was to get preg next mo then Ill be only 4-5 when we go?! I'm already high risk just because of my age (40). And if we aren't preggers by beginning of June we will need that vaca!! So what to do?? Cruises are hard to cancel even w/ins.