I am four days late, should I be worried?

I am four days late for my period and I am freaking out, should I be? I am on birth control so I'm used to my periods being regular for the most part. They normally come one-two days after i start the plasibos. I have had sex since my last period. Also, for the past two months I have been on numerous antibiotics because I have been sick, could this play a part in it? I have had all of my normals symptoms for before my period is about to start: Irritability, moodiness, cramps, etc...
Please help.

[Courttgx]

At this point in time, you may just be overthinking this. Pregnancy scares are usual. I would just wait a few more days, and if your period still does not come, then take a test. The fact that you have all of the symptons you would usually have before your period is a good sign. Your period being late may just be because of stress, or yes, possibly the antibiotics you have been taking. Try not to think about it until the possibility become really alarming, like being more then a week late.

[tam2girls]

I was under the impression that some antibiotics can cause the pill not to work and that you should use another method of birth control until you start your next month of pills. You are not to early to test if you have missed your period and this may ease your mind a little. Good Luck

[Victoria01]

I agree with tam2girls. Antibiotics can lessen the strength of birth control and make them pretty much useless, so there is a possibility you are pregnant. There is also a possibility that you're just late this month. I don't know what kind of birth control you are on, but I wonder if it is hormone based it might effect the outcome of a HPT. (I am not really sure about that as I have never taken birth control.) I would ask a doctor and have them test.

[Banana_Boat]

I got my period, yay. It must have been the stress of starting college and the antibiotics.
Thanks everyone!