do I have a low supply?

Erin • Mama to 3 beautiful girls
With my first daughter, I remember getting really engorged and in pain, one boob getting bigger than the other. However, I had to quit breastfeeding after less than a month because I went back to school and couldn't keep up pumping. 
This time, I'm off of work and home with my baby all the time. I pump and I breastfeed but I haven't been feeling engorged or sore. Okay, I've felt it three times total and it didn't hurt, they were just rock hard and huge.
Am I not getting engorged or sore because I'm on top of feeding/pumping since I'm home all the time. Or because I have a low supply? 
I'm nervous that I won't be able to pump enough for my baby once I'm not with her all the time.