not sure what type of bonus points might have been posted to your account and then removed. Also, there is no such think as rollover points. There are rollover nights, those in excess of what you earned and needed to retain your current elite level. You can find your current account balance after you sign in on the Marriott page, look at the top right and click on MY ACCOUNT and there you should find your balance.
I noticed that you posted your question toward the beginning of a month and stated your bonus points that had been there a week ago had disappeared. I am wondering if you are referring to the itemized list that shows you received bonus points? Each month the site resets the itemized list and you have to use the drop down menu by date to view the itemized stays and bonus points that were posted to your account.