Normal Periods

I've only ever used birth control once . I was on Depo which is  3 months , after that I never got on it again nor any other  birth control ...since then I've had 2 4 week periods one Sep-Aug and the other in Dec and this month I haven't had it??? Just a lot of clear discharge how long does it take for it to go back to normal?  And I haven't had any unprotected sex just back in November so I'm not worried