i was in the same boat when i starte synarel. i think they check day 21 to check for signs of ovulation - if you've o'd they give a little more time in case there's a chance of a natural little miracle - if your results on day 21 show no ovulation has occurred, they can start you straight away - i gues they're playing it safe - if you're progesterone is a little higher on day 21 they wait a little longer just in case IYKWIM? i know that i was checked for HCG, estrogen and progesterone before starting on synarel, but they main thing they were interested in was the progesterone...

good luck with the synarel - it tastes pretty ordinary once you get it running down the back of your throat - i generally have a glass of water, or try to clean my teeth around the same time that i do the spray to make sure it doesn't linger - and no big dramas here.