Personally I would be tempted, but would shop around a bit more first. I regret not getting a very nice maternity dress with my first pregnancy for a wedding (it was designed to be wearable when not pregnant as well).

Just a tip, check out places like Autograph, a lot of their styling works well with pregnancy and they go down to a size 14 now (sorry don't know how big or small you are, so please don't take offence). Last pregnancy I picked up all my "maternity" clothes from there and even found some tops on special for $5 each. Ok, they were not going out tops, but a nice enough for everyday to get me through the pregnancy.