On birth control and was on antibotics so just took Plan B now what to do about my birth control pills??

So I have been on birth control pills Ortho tri cyclen for over 3 years now. Never missed a pill or had much problems. I had gallbladder surgery Thursday Feb 17th and was prescribed the antibotic (antibiotic) Keflex. I took it for 5 days 4 times a day. I finished it on Tueday. Well lastnight (Thursday) I had unprotected sexual intercourse and I totally forgot that the Keflex might of affected my birth control. I never was informed by my doctor but I know most antibotics do. So this morning I called my doctor and spoke with the nurse she didnt think it would affect my birth control but she wasnt sure so she told me to call my pharmacy. I did and the lady there didnt think it would affect it either and she looked it up and didnt see anything about it. I was still wanting to make sure so I called a few other pharmacies and they said yes it would affect my birth control and I needed to use a backup method for a month. One pharamist told me that it would probably lessen my birth control pills by about 10 to 15%. I didnt want to risk anything so I went to my local clinic and got Plan B.
Im on my 3rd week of my birth control pills and I only have 2 active pills left until I start taking my surgar pills. Im suppose to start my period Wednesday. I asked one of the nurses at the clinic about it she said I should take the Plan B and then just continue taking my regular birth control pills like normal. After I got to the clinic I talked to another nurse about it she said I shouldnt take the last 2 active pills and should start taking my sugar pills Sunday so I can have my period and that the Plan B would cover for my other birth control pills because it would over load me with the horimones. So after I got home the nurse calls me back and said she spoke with the main nurse and she said I just needed to start a new pack either tonight or tomorrow. I told the nurse that I dont usually start a new pack until Sunday so she said I could wait until Sunday but until then I didnt have to worry about taking the last 2 active pills and I could just skip my period.
So now Im totally confused on what I should do. They told me 3 different things and the nurse seemed confused when I was asking her about starting it Sunday but she said it would be ok if I waited as long as I didnt have sex which Im not planning on it.
One of my friends told me that she went thru the samething and she just had to stop taking the active pills and start taking her sugar pills and had her period a week later. Does anyone know for sure on what the right thing is for me to do about my regular birth control pills?? Im so tired of all of these uncertain answers I just want to know what I need to do. If anyone else has went through this please let me know what you did about your birth control pills. Thanks for reading all of this. Sorry its so long and confusing I just want to know ASAP. Thanks in advance.