i am a 30 yr old married woman, the first day of my last period was 15th dec 2013.over the last week i have feeling very tired, feeling sleepy, urinating frequently, have light cramps in the lower abdominal area. I did a HPT in the morning it turned out negative. I went to a gynaecologist, she did a scan and said that there is no sac, but thickened endometrium of 11.2 mm, she asked me to carry out a serum HCG test. could i be preganant ?