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.