So confused ...

Im bleeding a week and 3 days before my next period. yesterday it was pink and today it is brown.it's a little more then spotting only there when I wipe.. I don't know when I ovulate because my cycle is irregular and short. I've had mild nausea, head aches, dizziness and sore nipples. I took a pt but it looked weird. One line going across and the other line going down but it wasn't all the way there. Could I be pregnant ? I was going to wait until o missed my period to test again. But last month it was almost 2 weeks late but I still got it so does anyone know what's going on ?