The general answer to your question is that anywhere in the tropics, there is a chance of contracting some serious diseases. Vaccines and prophylaxis medications can mitigate the risks but not completely eliminate them. Some life choices necessitate a major reorganization of your life in the short and long term.
Starting or adding to a family is once such life choice. When your focus is on having a baby, you shouldn't be jetting off to risky destinations as a way of passing the time until you give birth. If your concern is a healthy pregnancy resulting in a healthy child, stay home for a year and do that. If your focus is on travel, then do that and when you are ready to stay home and have a child, then do that.
Often, many attempt to have their cake and eat it too which for some doesn't work out the way they envision. From Marlaria, Dengue, Tyhpoid fever, Cholera, Chcikengunya, Zika, parasitic infections and other issues, gallivanting around the third world is not really compatible with the safe choice of staying home and devoting oneself to having a healthy pregnancy and producing a healthy baby.
Some things are just out of an individual's control. You don't get to choose which mosquito bites you so the safe choice is to stay away from mosquitoes that could be carrying tropical diseases which means staying out of areas where these diseases are known to exist. The more you move around a country, the more exposure you subject yourself to. In the end it only takes one infected mosquito.
It's your decision.