Question about medicine

So according to this app, I was suppose to start my period yesterday (March 8th) and I haven't started yet. I am also just getting over a bad sinus infection and I am taking antibiotics (augmentin) and hydrocodone cough syrup. I am probably worrying too much, but should I be concerned about being pregnant? I might just start tonight or tom. Who knows but figured I would ask since I am taking these medications. We are always very careful and use a condum everytime we have sex.