hey there
not sure re the temp fluctuations.. i think its best to take ur temp afteratleast 3 hours sleep and at the same time everyday. i would probably go with whatever the first temp u get is as the more u take it the more youve moved around and affected it.. i'm no expert though..
with the temp dips i dont think u have to have a significant temp dip before o its all about the 3 day rise.. then after o ur temp should stay up untill either an implantation dip and come back up or until a day or two before af arrives..