Hi. My partner and I had sex on the 28th January. I'm not sure if any sperm went inside me. I took an emergency contraceptive 48 hours later. I got my period February the 9th ( 23 days after the end of my last period). I took a home pregnancy test 19th of March (5 days late ), which came out negative. today is the 21st of March and I am 7 days late. Am I pregnant or is there any other reason for my delayed period? Please help me.