Okay, I need someone who will actually listen, and give advice based on my case.

On December 30, my boyfriend and I had sex with a condom, but it end up slipping off. In the end there is no doubt about it, unprotected sex was the case. I didn't worry about it because I knew my period always starts on the 5th of every month. It is now nearly the 7th (we in Australia on vacation, mate) and nothing of the usual is happening. I usually never no symptoms leading up to my period (tender breast, cramping, bloated-zip, nada). My period is probably the most predicable thing in my life. Yet, today I started feeling some mild cramping and I couldn't even put my bra on this morning my breast hurt soooo bad, but no period. I know it was only 6 days before my period, but is it possible that I could be and when should I take a test? Any more questions, just ask.