My daughter is 14 and I just found out she has been having unprotected sex for approximately 2 months now. Her last menstrual cycle she thinks was on the 21st of June. Almost one week ago she had a dark brownish discharge at night and once the following morning occur but no signs of pink or red blood. She has had normal heavy bleeding periods since she has been 12 years old. We did a home pregnancy test twice which have both came out negative and one blood test on the 23rd of July also negative. She has no signs of starting her period still and is experiencing nausea throughout the day and states her breasts around her nipple area is turning dark and tender. Since the blood test came out negative, is there any possibility it could be wrong, or can I be pretty sure that the test is accurate.