spotting, period, or pregnant? (maybe TMI)

My baby is 3 going to be 3 months old in a couple of days. Last Wednesday I had some brown spotting. It lasted only a few hours. I have had ewcm before and since the spotting I have some yellowish ewcm. Did anyone have this at 3 months ppt (while breastfeeding)? I am not sure if I could be pregnant or not.