Travel during first trimester

Mia • 35yrs old. Married. Dog Mom. Baby boy - Jan 2019! PCOS. Irregular cycles. TTC for baby #2 🙏🏽
Hi ladies, need your input and thoughts please. First off I am not pregnant but have been TTC for nearly a year. As we haven't been fortunate getting pregnant yet, I've decided to plan a vacation to enjoy life a little more untill we are blessed with a baby. We are planning on a trip to Croatia for about 2.5 weeks around mid-May this year.
However we are still TTC but going with the flow since it still hasn't happened yet. So im worried that now if we book a trip for May and I get pregnant anytime before that which would be amazing, is it safe to travel? 
 Depending when I would get pregnant (praying) I would probably be in the first trimester. 
The trip would have quite a bit of sight seeing, touring, walking around, island hoping. So not exactly just sitting back and relaxing everyday. 
My dilemma - what do I do???? Do I go ahead and book the trip? Is it safe to travel in first trimester, especially this kind of trip (mind u I would take it easy and try to not over exert).
Help! Thought? Input! Suggestions!