Hello, My Name Is Chelsea Hardin I Am 14 Years

Hello, my name is Chelsea Hardin I am 14 years old . I'm very confused on if I'm pregant. Ok so My last period was October 22nd 2015 I had unprotected sex November 10th . I was suppose to start my period November 22nd but I never did . So I took two at home pregnancy test and they came out negative. But I had pregnancy symptoms so I went to the doctor and they gave me a pregnancy test which also was negative so they checked me for Std's but I didn't have any. So they said just in case I had a infection they was going to give me anitbiotics to take for 7 days and when they run out to go back and take another pregnancy test but when my antibiotics ran out I never went back to take the test. I'm still waiting to go So on December 31st., I started bleeding like my period but I still Have pregnancy sympotoms so is this my period or am I just having break through bleeding because I'm pregant? Please help !!