I've had mastitis in the same (right) breast when breastfeeding my dd and now am 21 weeks pg, this pain is similar to the mastitis but I can't see a red line or anything.
Anyone had similar, I guess if it doesn't progress fast it isn't mastitis? - I remember too well how quickly it went from a bit sore to full on awful when I had it. And maybe it's not even possible when I'm pregnant not breastfeeding ?