Postpartum appointment

I have my 4 week postpartum check up in 2 weeks. Currently I'm only spotting using pantie liners, my stitches have dissolved and swelling has went away. (Had a 3rd degree tear). Will my OB give me the "ok" to start working out and having sex at my appointment? Has anyone got the ok at a 4 week postpartum check up? Also, I want to be put on birth control, will my doctor put me on them that soon? (So many questions because I thought there was only a 6 week check up until after I had my baby)