My period is 12 days late. It was suppose to come on Dec 30 and on Dec 20-21 I spotted. Now I started to bleed again its not heavy or filled up a pad Could this be my period?

Yes it could.

It is possible, periods often will be early or late, light or heavy, YOUR regular is what you should know, There is no one period for all.

Also if you are worried about pregnancy, you can do a test in about 3 days, with first urine of the morning, if this is not a full period