I understand your worry. Primolut N
is clearly contraindicated in pregnancy
. It was prescribed to you even before you were diagnosed to be pregnant and it was a onetime prescription.
I do not think it should worry about it. I do not also think it has caused any problem to your baby. It is schedule X drug and is contraindicated in women who are or may be pregnant.
To rule out any effects on your baby, get an ultrasound
Hope this helps.