I'm thinking of getting the depo-provera shot. does the depo-provera shot make your period lighter and regulate it like the pill?

Not exactly: The Depo-Provera shot usualy causes some irregular bleeding - it can last for a short time, say a month, or up to 6+ months, and sometimes it can cause more irregular/sporadic bleeding. Occasionally it can cause heavy, irregular bleeding. If a patient remains on the Depo-Provera shots for > 6-9 months it causes menses to stop in more than 90% of users. So it won't 'regulate' periods, but is likely to stop them.