Am I Spotting for more than 2 day?

Ok. So, never done this. First is I have a diagnosis of endrometriosis. However, I have for the past years been regular in that I will get a full menstruation that will start between the 4th and 10th. That is regular regularity so to speak. Around the 4th (maybe a day before) I saw light pink/grange when I wiped. This has now been occurring up until this current date. I had a small spot of brighter but for the most a light orange. In the beginning slight and light brown and some mucus (sorry for details!). As I said, it has continued, only is on and off. Depending on when I wipe. It does not necessitate a pad or anything. Around the 4th, I took a pregnancy test (digital). Then one a day later and it was negative. I still could get my full heavy flow by the 10th but this spotting thing, if that is what it is, is new. I did experience headaches last week, a rarity for me. Some cramping. No other relevant symptoms to suggest potential pregnancy...I would love to be pregnant. Any advice is welcomed!?