Thanks for the query.
During the period of lactation
some amount of hormonal imbalance is common and that can lead to irregular periods
As you are not using any contraceptive
method now, there is possibility of pregnancy.
So you once go for pregnancy test.
If the test comes negative, consult gynecologist once, get examined and take tablets to control the spotting. And also start hematenics.
Then you can choose some other contraceptive method or can go for permanent sterilization
depending on your choice.
For more details you can ask me directly through the premium forum.