3rd pregnancy symptoms?

This is my third pregnancy and this one is slightly different. I'm only 4 weeks 4 days. I'm due Dec 19th. I've been nauseous, sore breasts, the veins on my breasts are more prominent, and I'm so tired all the time but can't sleep very well, I'm also so hungry but can't ever find anything that sounds appetizing. And weirdest of all is when I bend over it hurts and feels like there is a rock under my belly button. Anyone else have this? With my other two pregnancys i didn't get that till after 10 weeks.