Hi there, I will suggest you the best possible treatment options.
First of all do not panic.
I will suggest you to get morning's first sample of urine tested for
pregnancy. If there is any doubt then blood beta HCG test and USG will be of help.
Usually,
progesterone hormone in the Nexplanon can lead to breast soreness. If your pregnancy tests are negative, then I will suggest you to start on Long acting form of vitamin B 6 along with
Folic acid supplementation for 3 months.
In case of positive pregnancy test,you can opt for the termination of pregnancy with
abortion pills under medical supervision safely till 9 weeks of pregnancy.
In case breast lesion is painful and reddens then surgical opinion is advisable.
Also, get urine routine examination and culture and sensitivity test done if increases urination is also associated with pain nad burning while passing urine.
If there is element of infection, a week long course of antibiotics like
Norfloxacin is advisable.
I hope this answer helps you.
Thanks.
Dr. Purushottam Neurgaonkar