I'm on birth control. But the weekend before I had sex I took 2 antibiotic pills. Friday and Saturday morning. Had sex that Monday night but made him pull out. We didn't even have sex that long. Tuesday morning early I took plan b. Like 7 hours later. I also went to the doc and got put on more meds for pneumonia but called my pharmacy and they said it shouldn't effect plan b. I'm supposed to start my period in 4 days but my gyno said plan b will effect my cycle. Ever since Friday I have felt sick beyond belief. So nauseous, stomach messed up, and I've had a horrible headache since last night. It's been over 2 weeks since I had sex. I took a pregnancy test yesterday and it was negative. I can not continue feeling this bad tho. Could my sickness be something else??