Baby wants to breast feed at 8 months.

My baby has never been exclusively breast fed. I had a pretty traumatic birth that caused my body to delay my milk and at about 3 days old she was having really bad jaundice which made me have to supplement until my milk came in. I never got that "super full" feeling that most breast feeding mom's talk about. I was never engorged or anything no matter how much or little she was feeding. And she was never making enough wet diapers so we ended up supplementing until around 3, months when all of my milk vanished. So she hasn't been breastfed since 3 months old and now at 8 months she keeps fighting me for the boob.. she gets so frustrated and I'm not sure why she's acting like this considering she never was fully breastfed. I bring her in bed with me every morning and just sit there resting my eyes and next thing I know she's trying to get to my boobs or is knawing on a nip. Has this ever happened to anyone? Is it normal developmentally?