Do antibiodics cancel out the depo-provera shot?

I was on an antibiodic(doxycycline hycate) for 2 weeks twice a day....and then had the day after I finished the dosage...later that night I remembered the little warning that you always here, be careful while on antibiodics. So I was hoping greatly that maybe the shot was different because it wasn't ingested. I don't know if I'm even in any danger since I'm spotting but i know that you can spot while pregnant also.