Losing too much weight?

Just wondering if anyone else has been losing (maybe) too much weight after their baby was born? Before I got pregnant i was 110lb & I'm about 5'6-5'7. I've always been thin naturally. My baby is almost 5 months old & now I'm about 103lbs (give or take a pound). I am breastfeeding which I know burns calories. I'm just wondering if this is common with breastfeeding or if I should make an appointment.

Side note is I ended up having gestational diabetes that wasn't diagnosed until after 30 weeks & my baby was 10lb 2 oz 😳 At my 6 week postpartum appointment I was tested again for diabetes & it came back good (that the diabetes went away.)