At this time, you're likely to be over the sickness and fatigue of the first trimester and not overburdened by, or uncomfortable from, a large belly yet. You can also rest easy knowing that your baby is developing well, with very little chance of a miscarriage occurring. Going on vacation is a great opportunity to spend quality time with your partner and pamper yourselves.
Relax and enjoy yourself, but be aware of the extra health precautions you need to take during pregnancy (see Traveling in Pregnancy). If you've had any complications, check with your doctor that it is safe to go on vacation.