My heart beats really fast now. Your body has to circulate more blood so it makes sense. When i'm laying in the tub staring at my belly I can see the beats in my belly and chest. I have to be still for a long time for my heart to rest up.

Your circulatory system is working twice as hard as normal. That's why women are so tired during the first trimester. Around the second trimester your body kind of gets used to it, but from what i've read, no one really knows why, lol. A woman's body is an extraordinary thing. It's a total pain in the ass, but extraordinary nonetheless.