For some women, increased CM is one of the first symptoms they have that indicates that they are pregnant. Not sure if pregnant CM is stretchy as I have never been pregnant before!
The temperature drop occurs within 48 hours of the arrival of AF. Most women have a dip in temps, then AF arrives. Some women have higher temps on the first day or two of AF and then they drop to pre-ovulation temps. There is not a set date to see a dip in temps because all weomen have varying lengths of cycles. Usually it is between 12-15 DPO.
Hope this helps!