Stuck in limbo

So I had what I think is a very faint positive on hpt yesterday and today dpo 12 and 13 (I think), but I've also been experiencing dark brown spotting which I would consider somewhat heavy over these two days as well. I want to say it is implantation but seems a bit too much for that - enough that I've had to change my liner twice yesterday and three times today. However, no menstrual cramps or other of my usual period symptoms. I've had mild aching of my breasts and urinary frequency over the last three days. I just wish I knew if this is all normal pregnancy, my period, or if I am losing another pregnancy. Anyone been through this?