I am on birth control and I was on antibiotics for 7 days due to a UTI about 3 weeks ago. I finished them up and the doctor told me to wait 7 days after I finished the pills. My boyfriend and I waited, but we had unprotected sex on the 5th day after I finished the antibiotics, but he pulled out before he finished. Then on the 7th day after I finished the pills we had unprotected sex all the way. I have an unusual pressure/tightness in my lower abdomen, back pain , clear/white discharge, headaches , slightly darkened nipples. Am I pregnant?