Possibly pregnant

So usually with my periods I get them at the very start of every month and they can last between 5-7 days but in November I had a normal period at the start of the month but then I got my period at the end of the month from the 27th of November to the 2nd of December. I had unprotected sex a few times during my fertile days In December considering I am trying to get pregnant but after my period finished on the 2nd two days later when I was really due for my period I only had spotting for two days and then that was it. I could really use some help or just someone to tell me what it could be, is there a possibility that I could be pregnant? 
Thankyou in advance xx