Promolut-N is the brand name of a hormone called norethisterone. It is a progesterone and is indicated for certain gynaecological disorders such as menorrhagia, premenstrual tension, dysfunctional bleeding etc. It is not indicated or used for medical termination of pregnancy.
Fortunately its short term use will not have any adverse effect on the baby when taken during first few days/weeks. Hence I agree with your doctor that you need not do anything further and certainly not try to abort.