having a period or something like it....

Hi,
Welcome to ehealthforum,
The lighter bleeding that you have could be probable decidual bleed. The symptoms (sore breasts, missed periods, headaches, nausea, feeling sick, nose bled, weight gain, feeling gassy, frequent urination) are suggestive of pregnancy. The tests done very early in pregnancy can show you false negative results as the kits are calibrated ones, so unless the hormone levels in urine reach a certain level, they do not show positive results. If you suspect chances of pregnancy, you should consider visiting your doctor/gynecologist for thorough examination (to confirm pregnancy related changes/signs in body) and blood/serum HCG level test (to confirm/rule out pregnancy accurately). If pregnancy gets confirmed, consider getting serial HCG levels tested. Doubling up of the hormone levels in 48-72 hours will show that pregnancy is going on smoothly. If levels are not adequate, then external hormonal supplements would be considered to be started to help you in preventing miscarriage/threatened abortion and help with continuing pregnancy smoothly. An ultrasound scan done would also help in confirming fetal wellbeing/viability and gestational age. Avoid any heavy work. Avoid lifting heavy objects or climbing stairs or standing for long periods of time. Look out for early danger signs like increase in bleeding/spotting, increasing intensity of abdominal cramps and back pain etc. Be in regular monitoring and follow-up with your treating doctor/gynecologist and report any new/abnormal symptoms immediately. Drink plenty of water. Take adequate rest. Maintain healthy diet.
Take care.