My Wife Is 15 Weeks Pregnant We Got Treated For

My wife is 15 weeks pregnant we got treated for chlamydia and her OB told her that we had to wait 3 weeks before we can have sex when I got treated the nurse told me that we had to wait 7 to 10 days so my question is how come her doctor told her that we had to wait 3 weeks but the nurse told me we don't have to wait 7 to 10 days