JK10 I was feeling exactly the same as you a couple of weeks ago!
I got my bfp, feeling happy and content, told my 'd'm, who proceeded to do nothing but put me on a downer.
Silly questions like am I sure its the right thing to do? (well, I was mother but now I dunno!)
I then felt so miserable about it, and thought oh gosh what have I done, what if it isn't the right thing to do, am I making mistake?!
And my bean was planned btw! We chose to get pregnant.
Now though, all that has passed. It is pretty normal to have doubt feelings and anxiety after first finding out. Its all the shock and the surprise and the hormones Don't let your doctors negative reaction play on your mind for too long.
I now know for certain it is most def the right thing for me and my family. How could it not be?! Don't doubt yourself anymore than is natural :)