I didnt know with my first till i was nearly 4 mths along, that one went very quickly for me!
This time around i found out at about 5.5 wks and funnily enough it has flown by, i keep looking at ticker and thinking it seems like last week it was on 5wks and i was thinking if only it would be on 20wks i will feel better, now my new goal is 35wks and that only days away, yah.
Then after that its just not that long at all, i keep saying only 6wks left like i cant believe it myself.
Would add what i did test wise etc, but seems everyone has pretty well much covered how it works

Congrats on pregnancy though