Sore nipples while breastfeeding, is this a sign of pregnancy?

I stopped nursing my first baby at 14 months, a month before I conceived our second. This time I’m nursing through (if I do get pregnant or am pregnant). Usually I don’t feel any discomfort in my chest, my daughter just turned one and exclusively nurses since I’m a SAHM. But this past week my nipples have been extra sensitive and sore, particularly the left side. Could this be an early pregnancy sign?