need information

My husband and I are TTC #1 and were asked to go on a cruise in December 2017.   Neither of us has ever been on one yet.  I'm curious if anyone has ever been on one while pregnant and what the risks are.  I'm not pregnant right now but we are trying and I'm just not sure if I should be planning a certain way depending on travel restrictions and cruise policies.  Can anyone tell me anything about this?