Am I pregnant?

Okay, so I know in order to find out, you obviously take a pregnancy test. But my questions more than that. I’m not trying for a baby, and I’m on birth control pills that I take every day at the same time so the possibility is very low. I had a “period” a couple days ago but it lasted maybe a day and it was very light.

The reason I think I could possibly be pregnant is because my breasts hurt so much. No lumps or anything new. When I was pregnant with my first this was how my breasts were and it was my first sign of pregnancy. Anyone else experience this? Should I test and when should I? Also I’m a year postpartum in case that means anything.