when is the right time to take a pregnancy test?

Well I was supposed to come on my period oct 31 or sometime October.. my period comes at different times every month . But this month I didn't get one at all. I thought I was having pms symptoms but I'm not sure. My breast are tender .. been like this for almost 3 weeks now. But it made two weeks Sunday since I had unprotected sex. I'm confused about this and I'm asking and looking up information but they telling me different things. I don't want to go to the doctors yet . Also I'm having this like hunger feeling to the point if I don't eat I cry or get really frustrated. Am I supposed to be hungry after I just ate ? Even food that smelled good before stank. And I can literally see my nipples popping out of every shirt I wear( stop wearing bras cause it irritates me) but now it don't hurt it's just swollen looking and tingling.