is it possible for a 12 week baby too sleep too much?she sleeps for 6 to 9 hours every night has a feed then goes back for another 1 to 3 hours.little naps throughout day maybe 2 hours in afternoon. has breast every 3ish hours during day.Plenty of wet nappies and usually 1 poo. She is lively and in great form while awake though fusses at boob for night time feed and maybe goes to sleep with very little. Not due to go back to doctor for four weeks for vaccination where I could get her weighed. Is all ok?