How could hackers continue to use my account half an hour after I changed the password??

How can I know they are not monitoring my emails now???

(On a side note when I followed Hotmail's instructions for what to do when hacked I found my husbands emails were being forwarded. I only noticed something was wrong because whenever he sent me an email after the hacking, it went into my Sent Folder instead of my Inbox. So we knew to look for mail forwarding. But Hotmail Account Settings has no info about where the mail was being forwarded to.)