not sure what to think??

I was due my period around the 27th Jan and I haven't had it yet. I'm not sure if I'm pregnant (not done a test yet).i am on no form of contraception either and haven't been for a while. I have some symptoms which include very very tender breasts; never been this painful before, slightly increased appetite but this usually happens, slight pain in the ovary area almost like I need to have a poo but the pain is in the wrong place for it to be a poo. I'm not pooing as much as I use to (go at least once a day)...I'm worried it may be something serious