Dear User Your Last menses was on 16 December 2017 and according to you you menses due on 19/January 2018 and had unprotected sex but your male partner ejaculate outside Medical sex on safe days cannot make you pregnant
even if your partner ejaculate inside of you. So it's not possible to be pregnant on the above mentioned date.
But still if you have problems do a urine pregnancy
test in pathology laboratory and not by your self Accordingly you can meet the doctors for further if you so desire with the reports.
Hopefully your questions is answered.