My last period was 7th of Dec. I usually get my periods every 28 days. This would make me due my period on Jan 3rd. It hasn't arrived. My breasts are very soar since the 3rd. They feel heavy and swollen. Normally they would only hurt slightly and just the day before I'd get my period. Today the end of my tummy is achy. I done a urine pregnancy test on the 3rd and again this morning. Both were negative. Any ideas?

Actually, even though you are regular, this is not uncommon. Many premenstrual symptoms are the same as pregnancy symptoms.

If you do not get your period within the next week then you should make an appointment with your physician for a blood test.

My last period was 7th of Dec. I usually get my periods every 28 days. This would make me due my period on Jan 3rd. It hasn't arrived. My breasts are very soar since the 3rd. They feel heavy and swollen. Normally they would only hurt slightly and just the day before i'd get my period. Today the end of my tummy is achy. I done a urine pregnancy test on the 3rd and again this morning. Both were negative. Any ideas??
OK thanks. Its just I take the blood thinner warfarin and it can be dangerous to a fetus and in my last pregnancy it was just caught in time.

Ah, I did not know about the warfarin. Yes, it can be VERY dangerous. In this case I am not sure if you should wait a week.

Contact your doctor for a blood test.