I had sex 5days ago the condom broke i took plan b but now i'm having cramping, back aches, head aches, trouble sleeping fatigue and mood swings. why?

Symptoms after sex: Assuming you are healthy, most likely your symptoms are related to anxiety & worries (what if).

Uncertain: Potential SE’s w emergency contraception: tender breasts; changes in menstrual flow (spotting, bleeding, early or late period or spotting instead of period); loose stools; dizziness; headache; nausea/ vomiting; abdominal discomfort or feeling tired. Pregnancy sympotms don't occur five days after sexual intercourse.