I took a pregnancy test 4days before my expected period and it was negative. My period was two days late took another and it was a bfp. According to my lmp on wed the 28th I would be 4weeks. Had my blood drawn. Dr said hcg was low at 73. Redraw on saturday. Now I am at 163. Dr said it's OK as long as the level is doubling, likely an early pregnancy. I am worried that the numbers are low...