jolene,
as long as u eating well, don't worry too much, eat balance meal. The weight gain will be lost after birth, if u plan to breastfeed, u will lost weight naturally. of course, we shouldn't diet if we breastfeeding.
i put a total of 9kg or so during my 1st pregnancy, on the lighter side, after birth, almost all gone because my baby is smaller. This time round, i actually hope to have a bigger baby as my daughter is kind of tiny at 2.54kg only....but its me who cannot stomach down alot of food during pregnancy.