Can Antibiotics Cause Delayed Periods?

Hi i got married about 1 and a half month back my last period was on the 16th of feb 2010. I have always been getting my periods very regularly but now i have missed my period this month.i have been taking antibiotics for my teeth baymox and enzoflam? has it affected my period.I have conducted 3 pregnancy tests .all are negative so why have i missed my period?