I Had A Regular Period The Second Week Of October.

I had a regular period the second week of October. And a week later I took a plan B bill. The week after that I bled for 4 days. In November I did not get a period. And I had unprotected sex 3 times. I got my "period" on December 28 to January 2. I have taken 3 pregnancy tests and they have all been negative. I am still concerned on whether I am pregnant or not.