Sir, I Want To Know About My Periods. I'm A

sir, i want to know about my periods. i'm a married women. last may 12th my periods was come correctly. after that i do sex with my husband one time 20-5-2018. after that i eat the i-pill tablet within 5 hours. then i have 3 days small bleeding starts 27-5-2018. then now i missed my periods june full. i do the pregnancy test the result was negative. im so tensed.pls help me