Question about CM, no picture.

I have long, somewhat irregular, cycles. They are 31-39 days more often than not, but have been as short as 29 days, or as long as 45.

What I’m wondering, though, I why I have so much Eggwhite CM? Sometimes there isn’t as much, but for around half of my cycle I have pretty consistent eggwhite CM. The only other CM I get is watery. But why do I get eggwhite so often?