the best time to visit Hawaii is in July
I would recommend booking it online at their website, http://disneycruise.disney.go.com, first because they don't leave daily. Then Disney provides transportation from the airport to the ship port if you need at an additional cost of approximately $70/person. When you book on their website, there is a section that asks if you will need ground transportation and that is when you can book it. Hope this helps!
To calculate workman's pay.
I have found Sun Country Airlines to be very economical. Usually Tuesdays and Wednesdays give you the best prices since they tend to be less traveled days.
You really should confer with your doctor regarding travelling at any stage of pregnancy. He or she knows your personal pregnancy history and will be able to give you the appropriate advice.