Will Trimethoprim Affect Contraceptive Pill Efficacy?

I am wondering if the antibiotic Trimethoprim will affect my contraceptive pill? I had sex 2 days before I started on the antibiotics which has made me really worried that my pill didn't work. I will have my 7 day break from the pill in 1 day so I dont know what to do (should i start a new packet straight away). Also Im not having sex this whole month to be on the safe side.