Im 13 weeks pregnant, and in the past 2-3 weeks im finding im tired and worn out all the time.. Isnt my energy levels meant to improve soon..? Not get worse..? Also if i stand up too quickly, my vision goes black and i lose my balance, and now and then my heart starts pounding out of my chest, as though ive just run a marathon or gotten a huge fright..? Im not sure if all this is normal or not but if anyone has any experience, can you suggest things to combat it and such..?