Can Irregular Period Be Normal After Breastfeeding?

hi, i'm a 31 year female. I had the copper coil fitted 6 months ago when i was breastfeeding my son. When i finished feeding my son my period returned, it was very heavy and lasted 7 days. I then had another bleed about 37 days later, this was very light and only lasted about 3 days. My question is whether you think this was period as it was so different from my first period. I'm aware periods can be irregular after breastfeeding but i'm wondering whether this is normal? Thanks