SHOULD I BE WORRIED?? IS THIS NORMAL??

hello ladies, hoping someone can help, so I just found out i was pregnant like almost 3 weeks ago... I had my first appointment this past Tuesday and the doctor told me that I was too early to be seen for an ultrasound and what I thought my EDD may be wrong (my calendar is off by like a week) is this normal? thinking im 5 weeks and a few days he tells me im 4 weeks!! and 2 days ago I had light pinkish spotting and yesterday I had light brownish spotting ... is this normal!.? is anyone having these issues with edd off as well?? also my hgc levels were a bit low but got my results that levels are going up as they should...