Spotting while exclusively BF

Ok, so I’m 7 weeks PP. I had my check up 12 days ago, everything was fine, no more bleeding or discharge.

Well, starting two days ago I’ve had a little spotting. Not much, maybe once a day in my underwear or when I wipe. Is this normal? I thought I wasn’t supposed to get my period until I stopped breast feeding. I know baby is getting enough because she’s growing well and goes through lots of full diapers per day.