I just found that I needed to eat every few hours to keep my (expanding) tummy from getting empty.
Which of course is very easily done on a cruise, isn't it?
I went on a cruise when I was one week after conception (officially 3 weeks "pregnant", they are so weird about counting time of gestation) and yes I was already having mega-symptoms (we knew I was pg...well DH knew the next day, but I had a feeling a couple days later). The week between wedding/conception and our cruise I went up a cup size, and the week of the cruise I went up another...thankfully I had brought a few sizes of bras!
By the second formal night I was very uncomfortable...even though I could still fit into my formal gown (it had only been 1 to 2 weeks!) I didn't WANT to be in it, my waist already HATED having anything against it.
I only had one day of being sick, but that started the early morning we left the Inside Passage and were in "real" water, LOL. And I wasn't wearing my SeaBands while I slept, so I'll never know the real cause for that.
The ONLY disappointment I had (beyond having to give up the "adult" mango tangoes...I had two before I finally decided "OK fine I am indeed pg" so no more rum) was that I was asleep by 8 almost every night. I managed to stay away for ONE show over 7 days, and I totally missed the midnight chocolate buffet. Dh tried to wake me up several times over a few hours, but I was just out cold. I'm a night owl so the exhaustion was very very weird, and NOT what I was expecting (my mom was an
amazon princess capable of moving the earth when she was pregnant, and I was sort of expecting that, not the sleeping all the time out of breath schlumpy chick I was).
So as long as you expect that you'll probably be OK.
Then again, I can't tell how many babies you've had. If you've had two, almost everyone I know who has had three says that third one was completely different from pregnancy on, so it might be good to expect anything.
And get FULL
trip insurance from the moment you book the cruise, the kind of insurance that lets you cancel for any reason, even "pre-existing", just in case you're just not up to it.