thank you for your query.
what you're experiencing is called breakthrough bleeding
and it is a common side affect of first time pill users.it occurs mostly as mid-cycle bleeding in users of combined oral contraceptive
this is due to the change in hormonal
it generally stops after one or two cycles.
If it does not resolve on its own then you can try switching to different pill formulations, or to switch to a non-hormonal method of birth control.
you can discuss this with your OB/GYN.
wishing you good health