Last period ended. feb 13th, i have sore swollen breats hard under both nipples to touch. to early to take a pregnacy test what else could it be?

Progesterone effect: Although this could be pregnancy, many women get very sore and swollen breasts during pms which occurs in the week prior to a period. Based on your last menses, you should be in this time of your cycle when Progesterone levels are high and breasts can respond as you have felt. Definitely take a pregnancy test though if your cycle is late.