Is ewcm after ovulation a sign of pregnancy?

Yes, Pregnancy can produce so much Estrogen that it can create mucus resembling egg-whites in some

Is it possible to be producing estrogen and getting ewcm as early as 2dpo until still now 5dpo

yes

progesterone starts the next day after ovulation and it causes the temp spike, sore/tender breast and nausea and such.

progesterone is created from the left over follice that turns into a Corpus Luteum

here is some information for you to read about the process

http://www.fertilityties.com/post/show/the-menstrual-cycle-ovulation-fertility-medications

also sorry I forgot to add progesterone levels to vary per hr and also estrogen levels can vary per cycle and that's why you see more signs one second and then the next second you see nothing very normal

Yes, however, cervical mucous is only an indicator of estrogen levels it is not an indicator of pregnancy.