<human>: I dont really even know where to start with this but I'm sort of freaking out at the moment so I turned to reddit. I'm 19 and a freshman at a liberal arts university thats about an hour from my hometown. 

I've been with my boyfriend for almost 10 months now and for the last five I've been on the birth control pill. It's sometimes suggested to use a back up method while on the pill but since we are both clean and I'm very good about taking my pill on time and not missing pills I chose not to.

I do, however, get frequent UTIs, including one that led to a kidney infection. I have read that some antibiotics can cancel out the pill, rendering it ineffective for the rest of that cycle. I began my last dose of antibiotics on Christmas day and my boyfriend has pulled out every time we've had sex since then. 
Recently my breasts have been very sore and I've had back pain, and I've gotten periodicly nauseous the past couple days. I finished my pill pack Saturday and should get my period this week but I havent gotten it yet. Sometimes it takes a little time to start, but no more than a day. 

I know the chances that I could actually be pregnant should be slim and that I'm probably overanalyzing everything and freaking myself out but I cant shake this feeling. My boyfriend has been incredibly supportive and telling me not drive myself crazy over it until we know something, but I know he's worried too. I have so much at stake here; I'm an NCAA athlete and declaring as an art and english double major this semester. I have so much that I want to do and I love my boyfriend but getting pregnant right now is the last thing I need or want. I've told myself that if I dont get my period by Wednesday that I'll take a test and find out for sure. But I just dont know what to do and I can't stop thinking about it. What would you do? Does anybody have any advice?

Could you distill the essence of the text into 1-3 sentences?
<bot>: 19 year old college student on the pill, afraid antibiotics interfered with it and may be pregnant. period should have started either sunday or today but hasnt yet.