Hello and welcome to HCM,
Contraceptives regularize the menstraul cycles and also reduce the amount of menstrual flow.
So, this could be just a side effect of contraceptive use.
The menstrual bleed caused with use of contraceptives is not true bleeding.
It is withdrawal bleeding so it is not as heavy or similar in duration as the normal menstrual flow.
The other entities that you have mentioned- fibroids, adenomyosis
and ovarian cyst
are normal findings in healthy females.
Fibroids and cysts need to be removed when they are very large in size or cause symptoms of bleedinf and/ or dysmenorrhea.
In case you are uncomfortable with the scant blood flow you can consult your gynecologist for clinical examination, investigations and appropriate management.
Thanks and take care
Dr Shailja P Wahal