S.R.
bless your heart, i know EXACTLY what you are going through. my son is 5 and in kindergarten as well, he has the exact same problems. his teacher tried to say that it was ADD/ADHD, absolutely not...he can sit and study without problems, play for a lengthy time without fail, he doesnt show any signs of add/adhd...so i know its not that. he does on the other hand get bored pretty quickly, sometimes i feel like i have add/adhd just to keep up with him HAHA. he is an only child, he has been in a few daycares since he was 2, didnt have the issues at daycare that he does in kindigarten...but i find there is less structure in some daycares than kindergarten. Its a whole new battle once they hit actual school.
I have grounded, taken things away, apanked, timed out, you name we've done it...the only thing that i've found that works with him is staying on his bottom and when he does do great in class, he gets rewarded for it at the end of the week. This is only done if he gets smiley faces all week without failure. He seems to have his good weeks and his bad weeks, his bad weeks are primarily when he comes home from visiting with his father for the weekend. There is NO structure what so eer at his dads house...therefore it makes it hard once he gets back home and starts his week. I have several friends that have gone through this same thing also, and they said by time their child reached 1st grade, they were much much betta. it takes time, its a big transition from daycare to regular school...juts have to be patient and never give up.
I suggest, like some of the others here, that you reward your child when he does well at school and at home. Give things back to him that were initially taken away...but do it slowly...I wish you so much luck, its difficult especially since your preggo and your hormones are up and down.
Bless you and many hugs sent your way!!!