Am I pregnant ?

So this is my story .. my period was supposed to start on the 19th of Dec ... I only ended up getting it on the 21 and it stoped on the 23 ... very light flow with a lot of brown blood .. I never get this ... and usually my nipples get sore around 1 week before I start AF nut his time it started hurting the day I got AF and now AF stopped and they are still sore... could I be pregnant or is this normal .. ohh and also I took a hpt the 19th and it was negative haven't tested since