Hello 
You 
menstruation date was 27 th October , sex on Nov 29th ( unprotected but pull out method).
Supposed to be on 28th Nov ( period ) . 
Again sex on Dec 21st.
According to your query , you are not pregnant .
Since your menstruation are irregular and according to menstruation cycle , your OVULATION  day was  9-10 Nov. 
So in my opinion , now you are having 
amenorrhea ( no menses ) , so no 
pregnancy .
Amenoorhea or irregular menses may be due to many possibilities , these are :
Hormonal imbalance, tension , PCOD ( Poly Cystic 
Ovarian Disease ,in young child bearing age group)etc.
So consult a Gynaecologist and get his opinion regarding irregular menses or amenorrhea.
In my opinion , no need of any pregnancy test.