Slight overbite, do i need extractions?

It depends: Some mild overbites can be reduced by proclining the lower dental arch, and /or retraction of upper anterior teeth if space permits. Your orthodontist is in the best position to answer your question based upon your records.

Severity: "overbite" is only one of the many factors that go into a comprehensive diagnosis and treatment plan. Orthodontists will do whatever they can to treat you "non-extraction", but if there isn't enough bone to support the result, extractions may be necessary. See a qualified orthodontic specialist for an informed evaluation.