You will probably gain 6.8 kgs during your pregnancy.
If you gained the average of the range above, this is where the weight would go (totals are rounded):
You:
Uterus 0.4 kgs
Breasts 0.1 kgs
Blood 0.5 kgs
Water 0.6 kgs
Fat 1.3 kgs
Subtotal 2.9 kgs
Your baby:
Fetus 3.4 kgs
Placenta 0.2 kgs
Amniotic Fluid 0.3 kgs
Subtotal 3.9 kgs
Total 6.8 kgs

will be interesting to see how much i end up gaining