Can u be pregnant w/o and increase in cm??

Cassie • Momma of Two Graci 5-7-15 Graeson 9-7-16! Angel Momma of Two Nov 2015 and Twin B Jan 19 2016!
Im in my 2WW and i have yellowish slippery cm this morning and not i have pasty white cm is that good or i dontmproduce that much to begin with i use preseed