Take a deep breath, several really, and calm down.
Did you do it?
Now...you've already made the firm decision that you don't want your baby to have vitamin K. Period. End of discussion.
The doctor is there to promote vaccines and other standard medical routines that are deemed healthy and necessary. THat's his *job* and he does it well. Keep this in mind.
Now you can firmly and confidently respond to him and anyone else that asks, You will not have this administered to your baby. Period. End of discussion.
Be calm and confident about it - you are as sure about this as the sun revolving the earth.
Now be that calm about your birth too - you're letting yourself get all frazzled and swayed by their suggestions.
Remember your birth intentions and your birth plan.
Who is your support during your birth? Are they on board with you?
Try not to waste your precious energy on who's right and wrong - focus it on what you want the birth to be like and go with the flow.
P.S. My original OB tried a scare tactic on me too when I refused a certain pregnancy blood test. I choose not to have the test anyway...or any vacs. Our baby is beautiful and growing spectacularly! If there are any problems, you and your baby will know it before the docs. You have strong instincts...keep going with and into them.