In astrology, how come the moon doesnt come in cancer as often as the other zodiacs?

Answer 1

the Moon does not move at the same rate every day.

It does NOT have a perfect circular orbit around the Earth. There is a time where it is closer to the Earth (perigree) and farthest from Earth (apogee)
When at perigee (when the gravitational force is strongest), the moon moves faster in its orbit, and slower at apogee.

The times quoted for rotation are the average time.

The time when it is moving fastest, or slowest can happen in any sign though, so it does not stay less time in Cancer. Maybe you were looking in an ephemeris (book of the planets & moon's positions) at a time when the faster rotation took place in Cancer.
At other times it will happen in other signs.

Answer 2

It does ....
It takes the Moon 27 days 7 hours and 43 minutes to travel thru all the Signs and Houses. The moon enters a new zodiac sign approximately every 2 1/2 days
Ej The January moon Calendar will give the accurate zodiac sign placement of the moon for any day that month, for this check http://www.astrologyguidance.com/moon-cal/moon-cal.htm
Check also http://lunarhouse.com/moon/moon_calendar.htm
http://www.khaldea.com/calcenter.shtml