Antibiotics usually counteract birth controls.
Don't know about any test to "verify" Depo has been taken. If you have a girlfriend and she claims to have had the shot, Depo is still not 100% effective at preventing pregnancy on its own. And it definitely doesn't protect against STDs.
I am trying to rule out any suspicions? I do have doubts about her and if possible i would like to verify.
The pill is effected by antibiotics, but i am not sure depo is effected.
Sounds like you need a new girlfriend, then. Sorry to be so blunt! And I know it has nothing to do with your question. But if you can't trust someone you shouldn't be in a relationship with them.
Yeah, I'm not sure if antibiotics affect Depo either. Most likely they do, though.
Unless you meant that you have suspicions she's pregnant but not being honest? I'm totally making assumptions, forgive me!