9 week old will not nap during the day


So my 9 week old will not nap during the day. We have spent up to an hour fighting over a nap before, and this has been going in for nearly 2 weeks. I've tried white noise, rocking, dark room, light room, no stimulants, pacifier, clean bum, full belly etc. I have gone to the doc and they say its fine as she is sleeping well at night (anywhere from 6-9hrs). She is happy, feeding, healthy and putting on weight. There is nothing physically wrong with her that the doc could see. She will do about 4 x 15-30min naps sometimes on her playmat, in the car or in the stroller only, and that's it. She goes down at 6pm and will be wide awake from 5am. I know the doc said its okay, but all the "online experts" say its not. Should I be worried and go back to the doc again for more tests?