Thanks for the query.
As you are in lactational amenorrhea
and having history of unprotected intercourse
, there is possibility of pregnancy.
The symptoms you mentioned are not sufficient to confirm the pregnancy.
So you once go for pregnancy test.
If the test comes positive, consult gynecologist and go for ultrasound to detect the gestational age
If test comes negative, consult gynecologist and take tablets for withdrawal bleeding. After that use some regular contraceptive
method to prevent pregnancy.
For more details you can ask me directly through the premium forum.