Late period

The past week or so I’ve been having cramps and my boobs have been hurting. Well I woke up this morning with a headache and almost felt sick like I had the flu. And throughout the day it went away. I’m still have pain in my boobs. I’ve been having back pain. My head hurts on and off and occasionally I feel like sick to my stomach but nothing bad. It lasts for a second and then goes away. I’m having light brown strings in my discharge. Any opinions?