They are definitely driving me crazy!!! Mostly because I just can’t wait for the cuteness. But also because I’m pregnant too. And I just need there to be babies somewhere!!!We use a marking harness but sometimes ewes don't mark and are bred, or mark and are not settled. At least it gives a couple days spread. if they don't lamb on the estimated due date we figure another 2 weeks since their cycles are usually 14-18 days apart. Much easier.
However, guessing how soon or how many by the size of the ewe or her bag isn't specific. I have had enormous ewes deliver a tiny single lamb. I have had skinny little ewes deliver huge twins. I have had ewes (and dairy does) that bagged a month ahead and sje that only come into their milk after delivery.
Like Bay says, their goal in life is to make you crazy. And no matter how large your flock grows you never get tired of newborn lambs!