Only eating 5-6 minutes on each side?

TKx2

The first few days DD was staying on each side for 12-15 minutes. Once my milk came in she dropped down to 5-6 minutes per side. She nurses every 3 hours during the day, then cluster feeds every hour from about 5-9. At night she's been going for a 3-4 hour stretch. Should I be concerned? I'm assuming she's getting enough because she's having plenty if wet diapers, pulls off herself, and isn't crying for more. Also, she's not emptying me on both sides. Should I pump when she's done? I had mastitis with DD1 and would like to avoid that at all costs. I also don't want my supply to dip since she's not eating that much. Thanks!