Pregnancy or paranoia?

I know there is no way to know for sure until i take a test, but i would like to know your opinion. If i am pregnant, i would have conceived two weeks ago. If i put pressure on my nipples at all they are soar, and I started noticing this last night. I have been much hungrier than usual the last couple of days, along with more tired. I usually never take naps, but I have the last three days. I never really have symptoms for getting my period until it actually starts, so i don't think it is this, but i'm not positive. I'm irregular with my period also, so i can't judge by that. Is it too early to be having symptoms and i'm paranoid or do you think i could really be pregnant? thanks in advance! (oh and when should i take a test?)