Hello Kirsten,
Thank you for posting on HCM
From your description you are having abnormal per vaginal bleeding which could be due to a good number of reasons. It is possible that you could be pregnant ( given your description) and having 1st trimester bleeding (spotting). This is common in some women. If you had unprotected sex with your husband 14 days to your next period, then your chances of getting pregnant at that period are greatly increased. Given the spotting nature of your bleeding, it can is possible for 1st trimester bleeding due to the
pregnancy ( early signs of placenter previa? but not specific). 2 pregnancy test done too early is normal they are negative because
beta hCG in urine has not yet reached detectable levels by the pregnancy
urine test strip. If you want immediate clarification, you will need another pregnancy test but with dosage of beta hCG in blood ( this will show immediate increased levels if you are pregnant) and/or do a pelvic
ultrasound ( you will need to see a gynobs). If you are unable to do those now, just wait for about a week and redo the urine pregnancy test again and if negative, then be rest assured that pregnancy is not the issue.
There can be other possible causes of abnormal menstrual flow such as infection (given the brown discharge), and other uterine diseases which would have to be identify by your gynobs.
Hope this helps and wish you the best.