Congrats on your pg hun!! I started feeling movement at around 21 weeks, remember that there is alot cushioning your little one right now so it is sometimes difficult to feel, rest assured you will start feeling them very soon! Have you had you 20 weeks scan - that should help you rest your fears too!

I also put on 6 kgs in the first 12 weeks and then 15 kgs all up, its normal to have your body adjust to this new person growing inside you, just try to eat healthily as possible and you will be fine! In a few weeks time it will all proportion itself out!
Wishing you well for the next few months!
xoxo