Welcome to HCM,
If you had sex during infertile period i.e safe period roughly means first or last week of your period then chance of pregnancy
is rare, provided you have regular period.
Now as 5 days are gone no medicine will work to stop pregnancy.
As you had last period on 9th February then what about the period expected in about 8-9th march ?
That is not made clear.
Ok and bye.